You may need to use the appropriate technology to answer this question.
A survey collected data on annual credit card charges in seven different categories of expenditures: transportation, groceries, dining out, household expenses, home furnishings, apparel, and entertainment. Using data from a sample of 42 credit cardaccounts, assume that each account was used to identify the annual credit card charges for groceries (population 1) and the annual credit card charges for dining out (population 2). Using the difference data, with population 1 − population 2, the sample mean difference was
d = $870,
and the sample standard deviation was
sd = $1,121.
(a)
Formulate the null and alternative hypotheses to test for no difference between the population mean credit card charges for groceries and the population mean credit card charges for dining out.
H0: μd ≠ 0
Ha: μd = 0
H0: μd < 0
Ha: μd = 0
H0: μd ≤ 0
Ha: μd > 0
H0: μd ≥ 0
Ha: μd < 0
H0: μd = 0
Ha: μd ≠ 0
(b)
Calculate the test statistic. (Round your answer to three decimal places.)
What is the p-value? (Round your answer to four decimal places.)
Can you conclude that the population means differ? Use a 0.05 level of significance.
The p ≤ 0.05, therefore we can conclude that there is a difference between the annual population mean expenditures for groceries and for dining out.The p > 0.05, therefore we can conclude that there is a difference between the annual population mean expenditures for groceries and for dining out. The p > 0.05, therefore we cannot conclude that there is a difference between the annual population mean expenditures for groceries and for dining out.The p ≤ 0.05, therefore we cannot conclude that there is a difference between the annual population mean expenditures for groceries and for dining out.
(c)
What is the point estimate (in dollars) of the difference between the population means?
$
What is the 95% confidence interval estimate (in dollars) of the difference between the population means? (Round your answers to the nearest dollar.)
$ to $
Which category, groceries or dining out, has a higher population mean annual credit card charge?
The 95% confidence interval ---Select--- contains is completely below is completely above zero. This suggests that the category with higher mean annual expenditure is ---Select--- groceries dining out .
In: Math
1.
Suppose a researcher is interested in carrying out a phase II clinical trial in order to assess the effectiveness of four different doses of an investigational new drug. Assume the following table represents the summary statistics revolving around the number of adverse events in the four fasting glucoses among the groups.
Fasting Glucose |
Treatment Group |
124 |
1 |
124 |
1 |
125 |
2 |
134 |
2 |
138 |
2 |
137 |
2 |
136 |
2 |
119 |
1 |
124 |
3 |
120 |
1 |
116 |
3 |
124 |
3 |
127 |
3 |
129 |
1 |
A) Calculate the MSW.
B) Calculate the MSB
a |
A) MSW=154.741 B) MSB=31.226 |
|
b |
A) MSW=186.198 B) MSB=29.714 |
|
c |
A) MSW=194.689 B) MSB=21.777 |
2.
A researcher is interested in the effectiveness of a new asthma medication at increasing the forced vital capacity (FVC) in children. The medicated spray to be used via inhaler has moved into phase II of clinical trials where five different treatment doses are being tested against the control best standard of care. Suppose the following incomplete ANOVA table summarizes the preliminary analysis for the study.
Sum of Squares |
df |
Mean Square |
|
Between Groups |
4032.2 |
||
Within Groups |
439 |
||
Total |
7492.7 |
A) Complete the ANOVA table
B) Calculate an F statistic and a pvalue.
a |
A) SSW=3469.5, dfB=5, dfT=444, MSB=806.44, MSW=7.90 B) F=102.1, pvalue ~0 |
|
b |
A) SSW=2561.2, dfB=10, dfT=125, MSB=502.14, MSW=11.2 B) F=123.8, pvalue ~1 |
|
c |
A) SSW=1259.0, dfB=15, dfT=236, MSB=678.24, MSW=9.11 B) F=99.5, pvalue ~0 |
In: Math
The recent default rate on all student loans is 6.2 percent. In a recent random sample of 314 loans at private universities, there were 8 defaults. |
Does this sample show sufficient evidence that the private university loan default rate is below the rate for all universities, using a left-tailed test at α = .010? |
(a-1) | Choose the appropriate hypothesis. |
a. | H0: ππ ≥ .062; H1: ππ < .062. Accept H0 if z < –2.326 |
b. | H0: ππ ≥ .062; H1: ππ < .062. Reject H0 if z < –2.326 |
|
(a-2) |
Calculate the z-score for the sample data using a left-tailed test at α = .01. (A negative value should be indicated by a minus sign. Round your answer to 3 decimal places.) |
zcalc |
(a-3) | Should the null hypothesis be rejected? | ||||
|
(b) |
Calculate the p-value. (Round your answer to 4 decimal places.) |
p-value |
(c) | The assumption of normality is justified. | ||||
|
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In: Math
A sample of 112 mortgages approved during the current year showed that 44 were issued to a single-earner family or individual. The historical percentage is 36 percent. At the .05 level of significance in a right-tailed test, has the percentage of single-earner or individual mortgages risen? (a-1) H0: π ≤ .36 versus H1: π > .36. Choose the right option. a. Reject H0 if zcalc > 1.645 b. Reject H0 if zcalc < 1.645 a b (a-2) Calculate the test statistic. (Round intermediate calculations to 2 decimal places. Round your answer to 4 decimal places.) Test statistic 1.645 (a-3) The null hypothesis should be rejected. True False (b) Is this a close decision? Yes No (c) State any assumptions that are required. a. nπ < 10 and n(1 − π) > 10 b. nπ < 10 and n(1 − π) < 10 c. nπ > 10 and n(1 − π) > 10 d. nπ > 10 and n(1 − π) < 10 a b c d
In: Math
We assume that our wages will increase as we gain experience and become more valuable to our employers. Wages also increase because of inflation. By examining a sample of employees at a given point in time, we can look at part of the picture. How does length of service (LOS) relate to wages? The data here (data96.dat) is the LOS in months and wages for 60 women who work in Indiana banks. Wages are yearly total income divided by the number of weeks worked. We have multiplied wages by a constant for reasons of confidentiality.
(a) Plot wages versus LOS. Consider the relationship and whether
or not linear regression might be appropriate. (Do this on paper.
Your instructor may ask you to turn in this graph.)
(b) Find the least-squares line. Summarize the significance test
for the slope. What do you conclude?
Wages = | + LOS |
t = | |
P = |
(c) State carefully what the slope tells you about the relationship
between wages and length of service.
(d) Give a 95% confidence interval for the slope.
( , )
worker wages los size 1 61.372 54 Large 2 42.7536 33 Small 3 45.7298 57 Small 4 59.9747 63 Small 5 66.9318 190 Large 6 47.0695 112 Small 7 49.306 41 Large 8 41.0451 49 Large 9 55.3925 29 Large 10 51.586 51 Small 11 48.8118 34 Large 12 47.6549 49 Small 13 51.9155 58 Small 14 49.4336 71 Large 15 49.0055 59 Large 16 67.1645 54 Large 17 41.0187 146 Large 18 66.6989 64 Small 19 37.3414 57 Large 20 41.1314 44 Large 21 68.2611 54 Large 22 49.2968 146 Small 23 41.31 71 Large 24 51.4378 131 Small 25 39.8553 92 Large 26 46.3618 137 Small 27 49.451 31 Small 28 41.2582 85 Large 29 56.6397 46 Large 30 43.6494 98 Large 31 43.9767 125 Small 32 44.4695 87 Large 33 45.9359 95 Large 34 42.7246 100 Small 35 45.1822 111 Large 36 67.6785 126 Large 37 47.3643 115 Large 38 44.4952 41 Small 39 41.0943 58 Large 40 43.894 133 Small 41 49.3584 49 Small 42 48.877 86 Small 43 55.4153 37 Large 44 52.4565 25 Small 45 79.1435 85 Large 46 47.3674 121 Small 47 37.8021 81 Large 48 38.0888 31 Large 49 40.4484 146 Small 50 45.4833 15 Large 51 53.525 38 Large 52 52.6821 102 Large 53 42.9239 18 Large 54 40.1348 168 Small 55 75.9808 72 Small 56 37.1931 24 Large 57 48.2541 36 Small 58 49.557 44 Large 59 79.727 28 Small 60 53.8476 56 Large
In: Math
Tire |
Steering |
Tread Wear |
Buy Again |
|
Goodyear Assurance TripleTred |
8.9 |
8.5 |
8.1 |
|
Michelin HydroEdge |
8.9 |
9 |
8.3 |
|
Michelin Harmony |
8.3 |
8.8 |
8.2 |
|
Dunlop SP 60 |
8.2 |
8.5 |
7.9 |
|
Goodyear Assurance ComforTred |
7.9 |
7.7 |
7.1 |
|
Yokohama Y372 |
8.4 |
8.2 |
8.9 |
|
Yokohama Aegis LS4 |
7.9 |
7 |
7.1 |
|
Kumho Power Star 758 |
7.9 |
7.9 |
8.3 |
|
Goodyear Assurance |
7.6 |
5.8 |
4.5 |
|
Hankook H406 |
7.8 |
6.8 |
6.2 |
|
Michelin Energy LX4 |
7.4 |
5.7 |
4.8 |
|
Michelin MX4 |
7 |
6.5 |
5.3 |
|
Michelin Symmetry |
6.9 |
5.7 |
4.2 |
|
Kumho 722 |
7.2 |
6.6 |
5 |
|
Dunlop SP 40 A/S |
6.2 |
4.2 |
3.4 |
|
Bridgestone Insignia SE200 |
5.7 |
5.5 |
3.6 |
|
Goodyear Integrity |
5.7 |
5.4 |
2.9 |
|
Dunlop SP20 FE |
5.7 |
5 |
3.3 |
The Tire Rack, America's leading online distributor of tires and wheels, conducts extensive testing to provide customers with products that are right for their vehicle. The following data show survey ratings (1 to 10, with 10 being the highest) for 18 summer tires. Develop an estimated regression equation that can be used to predict the Buy Again rating given based on the Steering and Tread wear rating. How many percent of the variation in the Buy Again variable could be predicted by Steering and Thread wear rating?
Note: put answers into decimal form, if your answer is 90.8765%, enter in 0.908765.
In: Math
We assume that our wages will increase as we gain experience and become more valuable to our employers. Wages also increase because of inflation. By examining a sample of employees at a given point in time, we can look at part of the picture. How does length of service (LOS) relate to wages? The data here (data493.dat) is the LOS in months and wages for 60 women who work in Indiana banks. Wages are yearly total income divided by the number of weeks worked. We have multiplied wages by a constant for reasons of confidentiality.
(a) Plot wages versus LOS. Consider the relationship and whether
or not linear regression might be appropriate. (Do this on paper.
Your instructor may ask you to turn in this graph.)
(b) Find the least-squares line. Summarize the significance test
for the slope. What do you conclude?
Wages = | + LOS |
t = | |
P = |
(c) State carefully what the slope tells you about the relationship
between wages and length of service.
This answer has not been graded yet.
(d) Give a 95% confidence interval for the slope.
( , )
worker wages los size 1 44.4711 150 Large 2 45.2146 21 Small 3 74.8957 123 Small 4 72.0558 80 Small 5 39.0496 83 Large 6 47.9774 73 Small 7 51.2293 86 Large 8 69.0781 179 Large 9 39.2668 39 Large 10 53.424 125 Small 11 51.8895 50 Large 12 42.1108 67 Small 13 50.9806 86 Small 14 41.6564 26 Large 15 64.8102 138 Large 16 38.3316 30 Large 17 70.1092 31 Large 18 59.5725 22 Small 19 72.6489 97 Large 20 48.6928 129 Large 21 65.3321 34 Large 22 46.696 56 Small 23 42.9948 100 Large 24 63.7128 106 Small 25 54.0511 170 Large 26 37.2906 56 Small 27 58.9101 44 Small 28 80.6583 206 Large 29 82.063 63 Large 30 68.5583 114 Large 31 48.3471 97 Small 32 43.8155 109 Large 33 58.983 16 Large 34 37.3826 23 Small 35 68.8845 63 Large 36 55.8785 167 Large 37 60.7873 46 Large 38 43.4198 16 Small 39 47.1446 77 Large 40 44.8549 121 Small 41 65.4524 29 Small 42 45.9087 72 Small 43 46.2893 28 Large 44 65.7419 114 Small 45 44.6151 37 Large 46 89.5987 173 Small 47 50.201 25 Large 48 79.3444 55 Large 49 44.7124 62 Small 50 41.2526 63 Large 51 67.4239 138 Large 52 80.865 51 Large 53 50.7154 86 Large 54 40.1463 165 Small 55 56.4553 29 Small 56 49.2739 82 Large 57 58.4318 17 Small 58 58.0383 127 Large 59 52.917 71 Small 60 62.8699 28 Large
In: Math
If a researcher found a Person correlation of r = 0.32 between aggression and frequency of binge drinking in a sample of n = 52 undergraduate students. Therefore, he can conclude that __________.
A. there is no significant relationship between these variables with either, p <.05 and p <.01
B. there is a significant positive relationship between these variables with p <.05 but not with p <.01.
C. there is a significant positive relationship between these variables with both, p <.05 and p <.01
D. there is a significant positive relationship between these variables with p <.01 but not with p <.05.
In: Math
In a fishing lodge brochure, the lodge advertises that 75% of its guests catch northern pike over 20 pounds. Suppose that last summer 65 out of a random sample of 88 guests did, in fact, catch northern pike weighing over 20 pounds. Does this indicate that the population proportion of guests who catch pike over 20 pounds is different from 75% (either higher or lower)? Use α = 0.05. (a) What is the level of significance? State the null and alternate hypotheses. H0: p = 0.75; H1: p ≠ 0.75 H0: p < 0.75; H1: p = 0.75 H0: p = 0.75; H1: p > 0.75 H0: p ≠ 0.75; H1: p = 0.75 H0: p = 0.75; H1: p < 0.75 (b) What sampling distribution will you use? The Student's t, since np > 5 and nq > 5. The Student's t, since np < 5 and nq < 5. The standard normal, since np < 5 and nq < 5. The standard normal, since np > 5 and nq > 5. What is the value of the sample test statistic? (Round your answer to two decimal places.) (c) Find the P-value of the test statistic. (Round your answer to four decimal places.) Sketch the sampling distribution and show the area corresponding to the P-value. WebAssign Plot WebAssign Plot WebAssign Plot WebAssign Plot (d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis? Are the data statistically significant at level α? At the α = 0.05 level, we reject the null hypothesis and conclude the data are statistically significant. At the α = 0.05 level, we reject the null hypothesis and conclude the data are not statistically significant. At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are statistically significant. At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are not statistically significant. (e) Interpret your conclusion in the context of the application. There is sufficient evidence at the 0.05 level to conclude that the true proportion of guests who catch pike over 20 pounds differs from 75%. There is insufficient evidence at the 0.05 level to conclude that the true proportion of guests who catch pike over 20 pounds differs from 75%.
In: Math
Socially conscious investors screen out stocks of alcohol and tobacco makers, firms with poor environmental records, and companies with poor labor practices. Some examples of "good," socially conscious companies are Johnson and Johnson, Dell Computers, Bank of America, and Home Depot. The question is, are such stocks overpriced? One measure of value is the P/E, or price-to-earnings ratio. High P/E ratios may indicate a stock is overpriced. For the S&P Stock Index of all major stocks, the mean P/E ratio is μ = 19.4. A random sample of 36 "socially conscious" stocks gave a P/E ratio sample mean of x = 17.5, with sample standard deviation s = 5.8. Does this indicate that the mean P/E ratio of all socially conscious stocks is different (either way) from the mean P/E ratio of the S&P Stock Index? Use α = 0.05. (a) What is the level of significance? State the null and alternate hypotheses. H0: μ = 19.4; H1: μ ≠ 19.4 H0: μ = 19.4; H1: μ > 19.4 H0: μ > 19.4; H1: μ = 19.4 H0: μ ≠ 19.4; H1: μ = 19.4 H0: μ = 19.4; H1: μ < 19.4 (b) What sampling distribution will you use? Explain the rationale for your choice of sampling distribution. The standard normal, since the sample size is large and σ is unknown. The Student's t, since the sample size is large and σ is unknown. The standard normal, since the sample size is large and σ is known. The Student's t, since the sample size is large and σ is known. What is the value of the sample test statistic? (Round your answer to three decimal places.) (c) Estimate the P-value. P-value > 0.250 0.100 < P-value < 0.250 0.050 < P-value < 0.100 0.010 < P-value < 0.050 P-value < 0.010 Sketch the sampling distribution and show the area corresponding to the P-value. WebAssign Plot WebAssign Plot WebAssign Plot WebAssign Plot (d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis? Are the data statistically significant at level α? At the α = 0.05 level, we reject the null hypothesis and conclude the data are statistically significant. At the α = 0.05 level, we reject the null hypothesis and conclude the data are not statistically significant. At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are statistically significant. At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are not statistically significant. (e) Interpret your conclusion in the context of the application. There is sufficient evidence at the 0.05 level to conclude that the mean P/E ratio of all socially conscious stocks differs from the mean P/E ratio of the S&P Stock Index. There is insufficient evidence at the 0.05 level to conclude that the mean P/E ratio of all socially conscious stocks differs from the mean P/E ratio of the S&P Stock Index.
In: Math
You wish to test the following claim ( H a ) at a significance level of α = 0.01 . H o : μ = 64.6 H a : μ < 64.6 You believe the population is normally distributed, but you do not know the standard deviation. You obtain a sample of size n = 55 with mean ¯ x = 56.7 and a standard deviation of s = 15.9 . What is the test statistic for this sample? (Report answer accurate to two decimal places.) test statistic = What is the p-value for this sample? (Report answer accurate to four decimal places.) p-value = The p-value is... less than (or equal to) α greater than α This test statistic leads to a decision to... reject the null accept the null fail to reject the null As such, the final conclusion is that... There is sufficient evidence to warrant rejection of the claim that the population mean is less than 64.6. There is not sufficient evidence to warrant rejection of the claim that the population mean is less than 64.6. The sample data support the claim that the population mean is less than 64.6. There is not sufficient sample evidence to support the claim that the population mean is less than 64.6.
In: Math
Let x represent the dollar amount spent on supermarket impulse buying in a 10-minute (unplanned) shopping interval. Based on a certain article, the mean of the x distribution is about $34 and the estimated standard deviation is about $9. (a) Consider a random sample of n = 110 customers, each of whom has 10 minutes of unplanned shopping time in a supermarket. From the central limit theorem, what can you say about the probability distribution of x, the average amount spent by these customers due to impulse buying? What are the mean and standard deviation of the x distribution? The sampling distribution of x is not normal. The sampling distribution of x is approximately normal with mean μx = 34 and standard error σx = $0.08. The sampling distribution of x is approximately normal with mean μx = 34 and standard error σx = $0.86. The sampling distribution of x is approximately normal with mean μx = 34 and standard error σx = $9. Is it necessary to make any assumption about the x distribution? Explain your answer. It is necessary to assume that x has an approximately normal distribution. It is necessary to assume that x has a large distribution. It is not necessary to make any assumption about the x distribution because μ is large. It is not necessary to make any assumption about the x distribution because n is large. (b) What is the probability that x is between $32 and $36? (Round your answer to four decimal places.) (c) Let us assume that x has a distribution that is approximately normal. What is the probability that x is between $32 and $36? (Round your answer to four decimal places.) (d) In part (b), we used x, the average amount spent, computed for 110 customers. In part (c), we used x, the amount spent by only one customer. The answers to parts (b) and (c) are very different. Why would this happen? The x distribution is approximately normal while the x distribution is not normal. The sample size is smaller for the x distribution than it is for the x distribution. The standard deviation is larger for the x distribution than it is for the x distribution. The mean is larger for the x distribution than it is for the x distribution. The standard deviation is smaller for the x distribution than it is for the x distribution. In this example, x is a much more predictable or reliable statistic than x. Consider that almost all marketing strategies and sales pitches are designed for the average customer and not the individual customer. How does the central limit theorem tell us that the average customer is much more predictable than the individual customer? The central limit theorem tells us that the standard deviation of the sample mean is much smaller than the population standard deviation. Thus, the average customer is more predictable than the individual customer. The central limit theorem tells us that small sample sizes have small standard deviations on average. Thus, the average customer is more predictable than the individual customer.
In: Math
In a recent year, the Better Business Bureau settled 75% of
complaints they received. (Source: USA Today, March 2, 2009) You
have been hired by the Bureau to investigate complaints this year
involving computer stores. You plan to select a random sample of
complaints to estimate the proportion of complaints the Bureau is
able to settle. Assume the population proportion of complaints
settled for the computer stores is the 0.75, as mentioned above.
Suppose your sample size is 198. What is the probability that the
sample proportion will be within 4 percent of the population
proportion?
Note: You should carefully round any z-values you calculate to 4
decimal places to match wamap's approach and calculations.
Answer =
(Enter your answer as a number accurate to 4 decimal places.)
In: Math
In a recent NY Times Editorial, Ross Douthat looks at the work of Sen and discusses how the "100 million missing women" has now increased to "160 million." He laments that the increase continues to demonstrate COMPLETELY the level of misogyny and the availability of abortions throughout the world. Based on your understanding of Emily Oster's research, what other alternate explanation(s) is/are there for some of these "missing women"?
In: Math
Given the following relationship:
Shoe Size | Height (inches)
7.5 | 66
8 | 67
8 | 68
10 | 71
10.5 | 70
11 | 73
a) Letting the variable x represent shoe size and y represent height, determine the least squares regression line and correlation coefficent.
b) Based on the correlation coefficient calculated above, can the least squares regression line be confidently used as a predictor of height? Why or Why not?
SHow the work detailed. Thank you
In: Math