5. Listed in the table below are the robbery and aggravated assault rates (occurrences per 100,000) for the 12 most populated U.S. cities in 2006:
City |
Robbery (x) |
Aggravated Assault (y) |
New York |
288 |
330 |
Los Angeles |
370 |
377 |
Chicago |
555 |
610 |
Houston |
548 |
562 |
Phoenix |
288 |
398 |
Philadelphia |
749 |
720 |
Las Vegas |
409 |
508 |
San Antonio |
180 |
389 |
San Diego |
171 |
301 |
Dallas |
554 |
584 |
San Jose |
112 |
248 |
Honolulu |
105 |
169 |
a. Calculate the standard error of the estimate.
b. Estimate the strength of the linear relationship between x and y.
In: Math
The paired data values for this test are
First Value | Second Value |
-9.68 | -9.89 |
-14.16 | -12.11 |
-16.16 | -8.24 |
-13.66 | -17.15 |
-14.05 | -14.28 |
-14.66 | -12.69 |
-11.58 | -11.69 |
-17.41 | -15.27 |
-13.89 | -12.18 |
-13.03 | -13.63 |
-14.13 | -12.36 |
There are 11 data pairs. In the test, subtract the First Value from the Second Value. Also,Δ0 = 0. Compute the test statistic t0
In: Math
In the survey sponsored by the Lindt chocolate company, 1708
women were surveyed and 85% of them said that chocolate made them
happier.
a) Is there anything potentially wrong with this survey?
b) Of the 1708 women surveyed, what is the number of them who said
that chocolate made them happier?
c)Use Excel to construct a 98% confidence interval estimate of the
percentage of women who say that chocolate makes them happier.
Insert a screenshot, write down the confidence interval and write a
brief statement interpreting the result.
(d) Use Excel to test the claim that when asked, more than 80% of
women say that chocolate makes them happier. Use a 0.02
significance level. (i.e. complete steps (a) to (e) similar to
question 3)
(e) Does your result from (d) contradict your result from (c)?
Explain.
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Why is sigmoid activation function not recommended for hidden units but is fine for an output unit?
In: Math
Let x represent the number of mountain climbers killed
each year. The long-term variance of x is approximately
σ2 = 136.2. Suppose that for the past 11 years,
the variance has been s2 = 109.2. Use a 1%
level of significance to test the claim that the recent variance
for number of mountain-climber deaths is less than 136.2. Find a
90% confidence interval for the population variance. (a) What is
the level of significance?
State the null and alternate hypotheses.
Ho: σ2 = 136.2; H1: σ2 < 136.2 Ho: σ2 < 136.2; H1: σ2 = 136.2 Ho: σ2 = 136.2; H1: σ2 > 136.2 Ho: σ2 = 136.2; H1: σ2 ≠ 136.2
(b) Find the value of the chi-square statistic for the sample.
(Round your answer to two decimal places.)
What are the degrees of freedom?
What assumptions are you making about the original
distribution?
We assume a uniform population distribution. We assume a binomial population distribution. We assume a exponential population distribution. We assume a normal population distribution.
(c) Find or estimate the P-value of the sample test
statistic.
P-value > 0.100 0.050 < P-value < 0.100 0.025 < P-value < 0.050 0.010 < P-value < 0.025 0.005 < P-value < 0.010 P-value < 0.005
(d) Based on your answers in parts (a) to (c), will you reject or
fail to reject the null hypothesis?
Since the P-value > α, we fail to reject the null hypothesis. Since the P-value > α, we reject the null hypothesis. Since the P-value ≤ α, we reject the null hypothesis. Since the P-value ≤ α, we fail to reject the null hypothesis.
(e) Interpret your conclusion in the context of the
application.
At the 1% level of significance, there is insufficient evidence to conclude that the variance for number of mountain climber deaths is less than 136.2 At the 1% level of significance, there is sufficient evidence to conclude that the variance for number of mountain climber deaths is less than 136.2
(f) Find the requested confidence interval for the population
variance. (Round your answers to two decimal places.)
lower limit | |
upper limit |
Interpret the results in the context of the application.
We are 90% confident that σ2 lies outside this interval. We are 90% confident that σ2 lies above this interval. We are 90% confident that σ2 lies below this interval. We are 90% confident that σ2 lies within this interval.
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A simple random sample of 50 accounts is taken from an account receivables portfolio of XYZ Ltd and the average account balance is $650. The population standard deviation o is known to be $70. Test the hypothesis that the population mean account balance is greater than a. $620 using the p-value approach and a 0.05 level of significance. b. Test the hypothesis that the population mean account balance is less than $800 using the critical value approach and a 0.05 level of significance. Test the hypothesis that the population mean account balance is different from $750. using the p-value approach and a 0.05 level of significance. C.
In: Math
In the following problem, check that it is appropriate to use the normal approximation to the binomial. Then use the normal distribution to estimate the requested probabilities. It is known that 76% of all new products introduced in grocery stores fail (are taken off the market) within 2 years. If a grocery store chain introduces 66 new products, find the following probabilities. (Round your answers to four decimal places.) (a) within 2 years 47 or more fail (b) within 2 years 58 or fewer fail (c) within 2 years 15 or more succeed (d) within 2 years fewer than 10 succeed
statistics. HELP!
In: Math
Take a simple experiment of rolling a pair of balanced dice. Each die has six sides, each side contains one to six spots. Let us define the random variable x to be the sum of the spots on the two dice. Display the probability mass function and the distribution function for the random variable x.
In: Math
Exercise 14-4 Algo Consider the following competing hypotheses: H0: ρxy ≥ 0 HA: ρxy < 0 The sample consists of 34 observations and the sample correlation coefficient is –0.58. Use Table 2. a. Calculate the value of the test statistic. (Negative value should be indicated by a minus sign. Round intermediate calculations to at least 4 decimal places and final answer to 2 decimal places.) Test statistic b. Approximate the p-value. p-value < 0.005 0.005 < p-value < 0.01 0.01 < p-value < 0.025 0.025 < p-value < 0.05 c. At the 5% significance level, what is the conclusion to the test? H0, we conclude that the population correlation coefficient between x and y is significantly different from zero. rev: 11_14_2015_QC_CS-31836 References
In: Math
An experiment to compare the spreading rates of five different
brands of yellow interior latex paint available in a particular
area used 4 gallons (J = 4) of each paint. The sample
average spreading rates (ft2/gal) for the five brands
were x1. = 462.0, x2. =
512.8, x3. = 437.5, x4. =
469.3, and x5. = 532.1. The computed value of
F was found to be significant at level α = 0.05.
With MSE = 480.8, use Tukey's procedure to investigate significant
differences between brands. (Round your answer to two decimal
places.)
w =
Which means differ significantly from one another? (Select all that apply.).
x1. and x2
x1. and x3
x1. and x4.
x1. and x5.
x2. and x3.
x2. and x4.
x2. and x5.
x3. and x4.
x3. and x5.
x4. and x5.
There are no significant differences.
In: Math
1. Introduction: Brief description of the study including the purpose and importance of the research question being asked.
2. What is the null hypothesis? What is the research hypothesis?
3. Participants/Sampling Method: Describe your sampling method. What is your sample size? Who is your population of interest? How representative is the sample of the population under study?
4. Data Analysis: Describe the statistical analysis. What is your variable? What is its level of measurement? What is your alpha level?
5. Results & Discussion: Did you reject the null hypothesis? What information did you use to lead you to your conclusion? Was your p value greater than or less than your alpha? NOTE: You can just make up numbers, but include your made-up p value
In: Math
Demand data on "Service Orders" for a particular service enterprise for the previous 12 months is as follows: 550, 652, 673, 707, 725, 752, 780, 797, 815, 836, 850, and 872. Problem 3b) Use the following three methods and prepare three forecasting tables with errors for the given demand data. • a 3-month Weighted Moving Average with the weights 0.6, 0.3, and 0.1 with the maximum weight going for the most recent data point into the past • Exponential Smoothing with smoothing constant = 0.9 • Linear Trend Regression
In: Math
Suppose a geyser has a mean time between eruptions of 66 minutes. If the interval of time between the eruptions is normally distributed with standard deviation
24 minutes, answer the following question.
What is the probability that a random sample of 38 time intervals between eruptions has a mean longer than 76 minutes?
The probability that the mean of a random sample of 38 time intervals is more than 76 minutes is approximately __________
(Round to four decimal places as needed.)
In: Math
A Gallup Poll released in December 2010 asked 1019 adults living in the Continental U.S. about their belief in the origin of humans. These results, along with results from a more comprehensive poll from 2001 (that we will assume to be exactly accurate), are summarized in the table below:
Response | Year: 2010 | Year: 2001 |
---|---|---|
Humans Evolved with God guiding (1) | 38% | 37% |
Humans evolved but God had no part in the process (2) | 16% | 12% |
God created humans in present form (3) | 40% | 45% |
Other / No opinion (4) | 6% | 6% |
Calculate the actual number of respondents in 2010 that fall in each response category as well as the expected number, assuming that the population follows the 2001 distribution. (please round to the nearest whole number)
Response | Observed 2010 | Expected 2010 |
---|---|---|
Humans Evolved with God guiding (1) | ||
Humans evolved but God had no part in the process (2) | ||
God created humans in present form (3) | ||
Other / No opinion (4) |
Conduct a chi-square test and state your conclusion.
The value of the test statistic is: .... (please round to two decimal places)
The p-value for this test is: .... (please round to four decimal places; you can use CHISQ.DIST Excel function)
State the conclusion.
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The mayor of a large city claims that 25 % of the families in the city earn more than $ 100,000 per year; 55 % earn between $ 30,000 and $ 100,000 (inclusive); 20 % earn less than $ 30,000 per year.
In order to test the mayor’s claim, 285 families from the city are surveyed and it is found that:
90 of the families earn more than $ 100,000 per year;
135 of the families earn between $ 30,000 and $ 100,000 per year
(inclusive);
60 of the families earn less $ 30,000.
Test the mayor’s claim based on 2.5 % significance level.
In: Math