Let (X_1, ..., X_k) be a multinomial distribution with probabilities p_1, ..., p_k in n independent trials. Calculate E(X_i), and COV(X_i, X_j) for 1 <= i, j <= k.
In: Math
3. [10 marks] A sample survey of 54 discount brokers showed that the mean price charged for a
trade of 100 shares at $50 per share was $33.77 and a sample standard deviation of $15.
a. [3] Develop a 95% confidence interval for the mean price charged by discount brokers for a trade of 100 shares at $50 per share.
b. [2] Explain, in context, what the interval you found tells you.
c. [3] What sample size would be necessary to achieve a margin of error of $2? Assume a
confidence level of 95%.
d. [2] Three years ago the mean price charged for a trade of 100 shares at $50 per share was
$39.25. Has the price dropped significantly? Justify.
In: Math
You wish to test the following claim ( H a ) at a significance
level of α = 0.002 . H o : p 1 = p 2 H a : p 1 > p 2 You obtain
86.6% successes in a sample of size n 1 = 732 from the first
population. You obtain 79% successes in a sample of size n 2 = 395
from the second population. For this test, you should NOT use the
continuity correction, and you should use the normal distribution
as an approximation for the binomial distribution.
ALL I NEED IS FOR SOMEONE TO SHOW ME HOW TO INPUTE THIS ON A
CALCULATOR TI 84...the 2-PropZ TEST doesnt accept decimals.
In: Math
In a recent Super Bowl, a TV network predicted that 39 % of the audience would express an interest in seeing one of its forthcoming television shows. The network ran commercials for these shows during the Super Bowl. The day after the Super Bowl, and Advertising Group sampled 105 people who saw the commercials and found that 40 of them said they would watch one of the television shows. Suppose you are have the following null and alternative hypotheses for a test you are running: H 0 : p = 0.39 H a : p > 0.39
In: Math
To identify regional groupings of market segments it is useful to use which of the following research tools? Select one: a. Cluster analysis b. Factor analysis c. Simple random sampling d. Open-ended questions
The following marketing research technique(s) is used for perceptual mapping: Select one: a. correlation and regression b. conjoint analysis c. t-tests and ANOVA d. multidimensional scaling
In: Math
Toyota company prides themselves on customer service. they have been trying to determine exactly how long it takes, from start to finish, to buy a car at their dealerships. they have determined that the two parts of the transaction (showroom and service) follow the normal model. showroom has a mean time of 3.5 hours with a standard deviation of 1.5 hours. service has an average time of 2 hours with a standard deviation of 0.5 hours.
a) What is the mean and standard deviation of the difference between the showroom and service average waiting time.
b) What is the probability that it will take a customer longer during the service portion of the transaction.
c) Why does the standard deviation always increase when we add or subtract the means of two distributions.
In: Math
There are 3 SPSS outputs in this homework assignment. The questions for each output are listed below. Please type your answers into this word document and submit it as an attachment in the assignment tab.
Q1. Researchers were interested in determining whether background music helped or hindered students’ performance on a math test. Students were randomly assigned to 1 of 3 groups: 1) no music; 2) music only; and 3) music with lyrics. Students were then given a math exam, scores which could range from 0 to 100.
|
N |
Mean |
Std. Deviation |
Std. Error |
95% Confidence Interval for Mean |
||
|
Lower Bound |
Upper Bound |
|||||
|
No music |
250 |
77.59 |
13.055 |
.826 |
75.96 |
79.21 |
|
Music only |
250 |
78.10 |
13.357 |
.845 |
76.44 |
79.77 |
|
Music and lyrics |
250 |
78.97 |
13.263 |
.839 |
77.32 |
80.62 |
|
Total |
750 |
78.22 |
13.221 |
.483 |
77.27 |
79.17 |
|
ANOVA |
|||||
|
minutes |
|||||
|
Sum of Squares |
df |
Mean Square |
F |
Sig. |
|
|
Between Groups |
244.595 |
2 |
122.297 |
.699 |
.497 |
|
Within Groups |
130668.664 |
747 |
174.925 |
||
|
Total |
130913.259 |
749 |
|||
In: Math
2. An experiment was conducted by a physiologist to determine whether exercise improves the human immune system. Thirty subjects volunteered to participate in the study. The amount of immunoglobulin known as IgG (an indicator of long-term immunity) and the maximal oxygen uptake (a measure of aerobic fitness level) were recorded for each subject. The data can be found in the file marked AEROBIC. You will need to use the Data Analysis - Regression Function for this problem, as well as some graphing functions.
a. Construct a scattergram for the IgG-maximal oxygen uptake data.
b. Hypothesize a probabilistic model relating IgG to maximal oxygen uptake.
c. Fit the model to the data. Is there sufficient evidence to indicate that the model provides information for the prediction of IgG, y? Test using α = .05.
d. Does a second-order term contribute information for the prediction of y? Test using α = .05.
| Subject | IgG | Max Oxy |
| 1 | 881 | 34.6 |
| 2 | 1290 | 45.0 |
| 3 | 2147 | 62.3 |
| 4 | 1909 | 58.9 |
| 5 | 1282 | 42.5 |
| 6 | 1530 | 44.3 |
| 7 | 2067 | 67.9 |
| 8 | 1982 | 58.5 |
| 9 | 1019 | 35.6 |
| 10 | 1651 | 49.6 |
| 11 | 752 | 33.0 |
| 12 | 1687 | 52.0 |
| 13 | 1782 | 61.4 |
| 14 | 1529 | 50.2 |
| 15 | 969 | 34.1 |
| 16 | 1660 | 52.5 |
| 17 | 2121 | 69.9 |
| 18 | 1382 | 38.8 |
| 19 | 1714 | 50.6 |
| 20 | 1959 | 69.4 |
| 21 | 1158 | 37.4 |
| 22 | 965 | 35.1 |
| 23 | 1456 | 43.0 |
| 24 | 1273 | 44.1 |
| 25 | 1418 | 49.8 |
| 26 | 1743 | 54.4 |
| 27 | 1997 | 68.5 |
| 28 | 2177 | 69.5 |
| 29 | 1965 | 63.0 |
| 30 | 1264 | 43.2 |
In: Math
Use the table below to answer questions 4.5 – 4.7: This table contains the same client data as the first table. This time, though, the instructor is interested in knowing how his clients’ other activities might impact their average cycling speed in spin class. He notes that half of his clients also ride bikes outside during the week, while the other half of his clients do not bike anywhere except spin class.
|
Rides Outside |
Only Spin | Rides Outside | Only SPin | Rides outside | only spin |
|---|---|---|---|---|---|
| 20 | 15 | ||||
| 17 | 17 | ||||
| 18 | 19 | ||||
| 22 | 17 | ||||
| 21 | 17 | ||||
| 18 | 16 | ||||
| 17 | 18 |
Average Speed M = 19 M = 17
4.5 Calculate SS for each sample of spin class clients (the portion who ride outside and the portion who only do spin class). Show Work by inserting numbers into the table to show intermediate steps Rides Outside SS = Only Spin Class SS =
4.6 Calculate s for each group Rides Outside s = Only Spin Class s =
4.7 Based on the statistics you have computed, does there appear to be any difference in average speed between those who bike outside and those who only bike during spin class?
Explain why or why not?
In: Math
| Plot | Nutrients added | # of species |
| 1 | 0 | 36 |
| 2 | 0 | 36 |
| 3 | 0 | 32 |
| 4 | 1 | 34 |
| 5 | 2 | 33 |
| 6 | 3 | 30 |
| 7 | 1 | 20 |
| 8 | 3 | 23 |
| 9 | 4 | 21 |
| 10 | 4 | 16 |
What effect do nutrient additions have on plant species diversity? Long-term experiments at the Rothamstead Experimental Station in the U.K. sought to investigate the relationship, with some interesting findings.
The data can be found in the linked Google Sheets
document - you'll want to copy it to Excel and use the
Data Analysis ToolPak.
1) Produce a scatter plot of the data (click here for a generic
youtube video on creating a scatter plot from excel data - this is
for informational purposes only - it's not your data)
2) Add the least-squares regression line to your scatter plot. (click here for a generic youtube video on adding trendlines to scatter plots - this is for informational purposes only - it's not your data)
3) Test the hypothesis of no treatment effect on the number of plant species.
In: Math
A physician with a practice is currently serving 280 patients. The physician would like to administer a survey to his patients to measure their satisfaction level with his practice. A random sample of 22 patients had an average satisfaction score of 8.3 on a scale of 1-10. The sample standard deviation was 1.3 . Complete parts a and b below. a. Construct a 99% confidence interval to estimate the average satisfaction score for the physician's practice. The 99% confidence interval to estimate the average satisfaction score is left parenthesis nothing comma nothing right parenthesis . (Round to two decimal places as needed.)
In: Math
Recent incidents of food contamination have caused great concern among consumers. An article reported that 39 of 80 randomly selected Brand A brand chickens tested positively for either campylobacter or salmonella (or both), the leading bacterial causes of food-borne disease, whereas 62 of 80 Brand B brand chickens tested positive.
a)Does it appear that the true proportion of non-contaminated Brand A chickens differs from that for Brand B? Carry out a test of hypotheses using a significance level 0.01. (Use p1 for Brand A and p2 for Brand B.)
Calculate the test statistic and P-value. (Round your test statistic to two decimal places and your P-value to four decimal places.)
z= P-value =
b)if the true proportions of non-contaminated chickens for the Brand A and Brand B are 0.50 and 0.25, respectively, how likely is it that the null hypothesis of equal proportions will be rejected when a 0.01 significance level is used and the sample sizes are both 60? (Round your answer to four decimal places.)
In: Math
A supermarket is trying to decide whether to accept or reject a shipment of tomatoes. It is impossible to check all the tomatoes for size, but they desire an average weight of 8 ounces (they neither want too large nor too small).
(a) State the hypotheses.
(b) A random sample of 25 tomatoes yields an average weight of 7.65 ounces and a standard
deviation of 1.15 ounces. Calculate the test statistic and the p-value.
(c) Would you reject H0, or fail to reject H0 at 5% level of significance?
(d) Should the supermarket reject the shipment? Explain.
(e) To what type of error are you subject to?
In: Math
Collect data from 30 people from your work, school, neighborhood, family, or other group. Ask a quantitative question, such as, “How many pets do you have?” or “How many college classes have you taken?” Explain your population, sample, and sampling method and what level of measurement your data is (nominal, ordinal, interval, or ratio). Use technology ( Excel) to create a Histogram of your data and explain the shape of the distribution (bell-shaped, uniform, right-skewed, or left-skewed) and possible reasons why the distribution is this shape. Explain the importance of this data, what you find interesting about the data, and why the public should know. Look up a newspaper, e-pub, or journal article that confirms or denies the results of your small study.
Please explain briefly.
In: Math
7. A certain drug is used to treat asthma. In a clinical trial of the drug, 20 of 286 treated subjects experienced headaches (based on data from the manufacturer). The accompanying calculator display shows results from a test of the claim that less than 12% of treated subjects experienced headaches. Use the normal distribution as an approximation to the binomial distribution and assume a 0.05 significance level to complete parts (a) through (e) below.
a. Is the test two-tailed, left-tailed, or right-tailed?
Right tailed test
Left-tailed test
Two-tailed test
b. What is the test statistic?
Z=
(Round to two decimal places as needed.)
c. What is the P-value?
P-value=______
(Round to four decimal places as needed.)
d. What is the null hypothesis, and what do you conclude about it?
Identify the null hypothesis.
A:Ho<0.09
B:Ho>0.09
C:Ho:p≠0.09
D:Ho:p=0.09
Decide whether to reject the null hypothesis. Choose the correct answer below.
A.Reject the null hypothesis because the P-value is greater than the significance level, alpha.
B.Reject the null hypothesis because the P-value is less than or equal to the significance level, alpha.
C.Fail to reject the null hypothesis because the P-value is greater than the significance level, alpha.
D.Fail to reject the null hypothesis because the P-value is less than or equal to the significance level, alpha.
e. What is the final conclusion?
A.There is not sufficient evidence to support the claim that less than 9% of treated subjects experienced headaches.
B.There is not sufficient evidence to warrant rejection of the claim that less than 9% of treated subjects experienced headaches.
C.There is sufficient evidence to warrant rejection of the claim that less than 9% of treated subjects experienced headaches.
D.There is sufficient evidence to support the claim that less than 9% of treated subjects experienced headaches.
In: Math