A researcher is interested in whether the variation in the size of human beings is proportional throughout each part of the human. To partly answer this question they looked at the correlation between the foot length (in millimeters) and height (in centimeters) of 30 randomly selected adult males. The data is provided below. Use Excel to calculate the correlation coefficient r between the two data sets. Round your answer to two decimal places.

Foot length (mm)   Height (cm)
244.9   159.2
248.5   164.8
248.1   173.7
252.3   171.7
251.6   164.6
256.5   171.4
240.3   179.7
252.7   183.1
259.7   183.2
263.3   177.9
245.7   181.6
261.0   172.9
256.6   185.2
256.0   169.6
254.7   169.0
248.1   177.6
255.9   181.9
259.4   180.4
277.6   173.0
287.7   175.0
281.2   189.6
269.0   174.1
288.4   176.1
281.8   189.7
289.1   182.7
283.2   186.0
292.5   177.8
285.4   187.7
287.5   190.5
276.8   194.1

R=

5.A survey of 15 randomly selected employees from Bob’s factory was taken to find out how many sick days they took due to colds and flu last year. Suppose Bob didn’t take a random sample. Suppose the employees in the sample were those who responded to an advertisement Bob put out to the whole company, looking for volunteers to participate in the survey. What kind of error would be made here? THERE IS ONLY ONE CORRECT ANSWER – CHECK YOUR LECTURE NOTES.

a.Undercoverage

b.Nonresponse

c.Bias due to a self-selected sample

d.None of the above

6.A statistics student wants to know what OSU students think about parking on campus. To obtain a sample of 20 students, he knocks on the doors of residents in his dorm until he finds 20 people home who can take his survey about parking. This is a:

a.Simple random sample

b.Stratified sample

c.Convenience sample

Question 12 (1 point)

The coefficient of determination for the above bivariate data is:

Question 12 options:

A survey of several 9 to 11 year olds recorded the following amounts spent on a trip to the mall: $20.70, $20.82, $12.32, $19.53, $24.43

Construct the 98% confidence interval for the average amount spent by 9 to 11 year olds on a trip to the mall. Assume the population is approximately normal.

Step 1 of 4: Calculate the sample mean for the given sample data. Round your answer to two decimal places.

Step 2 of 4: Calculate the sample standard deviation for the given sample data. Round your answer to two decimal places.

Step 3 of 4: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

Step 4 of 4: Construct the 98% confidence interval. Round your answer to two decimal places.

The U.S. Census Bureau conducts annual surveys to obtain information on the percentage of the voting-age population that is registered to vote. Suppose that 608 employed persons and 719 unemployed persons are independently and randomly selected, and that 318 of the employed persons and 269 of the unemployed persons have registered to vote. Can we conclude that the percentage of employed workers ( p1 ), who have registered to vote, exceeds the percentage of unemployed workers ( p2 ), who have registered to vote? Use a significance level of α=0.01 for the test.

Step 1 of 6: State the null and alternative hypotheses for the test.

Step 2 of 6: Find the values of the two sample proportions, pˆ1p^1 and pˆ2p^2. Round your answers to three decimal places.

Step 3 of 6: Compute the weighted estimate of p, p‾p‾. Round your answer to three decimal places.

Step 4 of 6: Compute the value of the test statistic. Round your answer to two decimal places.

Step 5 of 6: Determine the decision rule for rejecting the null hypothesis H0H0. Round the numerical portion of your answer to two decimal places.

Step 6 of 6: Make the decision for the hypothesis test.

Q) Let Xbe a discrete random variable representing the maximum value of the two numbers on

A major oil company has developed a new gasoline additive that is supposed to increase mileage. To test this hypothesis, ten cars are randomly selected. The cars are driven both with and without the additive. The results are displayed in the following table. Can it be concluded, from the data, that the gasoline additive does significantly increase mileage?

Let d=(gas mileage with additive)−(gas mileage without additive). Use a significance level of α=0.05 for the test. Assume that the gas mileages are normally distributed for the population of all cars both with and without the additive.

Step 1 of 5: State the null and alternative hypotheses for the test.

Step 2 of 5: Find the value of the standard deviation of the paired differences. Round your answer to two decimal places.

Step 3 of 5: Compute the value of the test statistic. Round your answer to three decimal places

Step 4 of 5: Determine the decision rule for rejecting the null hypothesis H0H0. Round the numerical portion of your answer to three decimal places.

Step 5 of 5: Make the decision for the hypothesis test.

A developmental psychologist would like to know whether there is a difference in the sociability scores of children according to the number of siblings they have. He chose three random samples of n = 5 children each according to three groups and measured their level of sociability using a standardized test. The scores are shown in the table below. Do the scores indicate significant differences among the three groups?

a. Using the 5 steps of hypothesis testing, test at α .05. (15 pts)

b. Conduct two post hoc tests, Tukey’s HSD Test and the Scheffe Test, both at α .05, and compare your answers. (9 pts)

Need help with the ten step by hand ANOVA ... specifically the sum of squres/between/within calculations in the hypothesis testing

and the steps associated with the post hoc tests

Thank you!!

Consider two stocks with returns RA and RB with the following properties. RA takes values -10 and +20 with probabilities 1/2. RB takes value -20 with probability 1/3 and +50 with probability 2/3. Corr(RA,RB) = r (some number between -1 and 1). Answer the following questions

(a) Express Cov(RA,RB) as a function of r

(b) Calculate the expected return of a portfolio that contains share α of stock A and share 1−α of stock B. Your answer should be a function of α (c) Calculate the variance of the portfolio from part B (Hint: returns are now potentially dependent)

(d) What value of α* minimizes the variance of the portfolio? Your answer should be a function of r, denoted by α*(r).

(e) For what range of values for r is your α*(r) 6 1? What is the solution to the above problem if r is outside of that range? (Hint: draw a graph and find α* ∈ [0,1] that minimizes variance) (f) Is α*(r) increasing or decreading? (Hint: take the derivative with respect to r)

(g) Which r wouldtheinvestorprefertohave, positiveornegative? Whatistheintuition for that result? 3

7. Hunting :

The probability that an eagle kills a rabbit in a day of hunting is 10%. Assume that results are independent for each day.

(a) Write the probability mass function for the number of days until a successful hunt.

(b) What is the probability that the first successful hunt occurs on day five?

(c) What is the expected number of days until a successful hunt?

(d) If the eagle can survive up to 10 days without food (it requires a successful hunt on the 10th day), what is the probability that the eagle is still alive 10 days from now?

Hogg's Probability and Statistical Inference (9th Edition) - Problem 1.4-20E - How is this problem solved?

Hunters A & B shoot at a target with probabilities of p1 and p2, respectively. Assuming independence, can p1 and p2 be selected so that P(zero hits)=P(one hit)=P(two hits)?

A national organization that promotes good local government management (ICMA) is interested if a city’s region is related to privatized waste collection.

Privatized                     Government
EAST 20                                40

WEST 10                               30

SOUTH 30                             40

1. Provide null and alternative hypotheses in formal terms and layperson's terms for the chi-square two sample test.

2. Do the math and reject/accept at a=.05

3. Explain the results in layperson's terms

The local library if they get more patrons visiting by shifting some early morning hours to evening. They take a sample of days with morning hours included 8-5pm compared to 12-9pm.

8am-5pm hours: 50, 40, 60, 60, 70, 35, 40

12-9 PM hours : 40, 80, 70, 60, 85, 90, 70

1. Provide null and alternative hypotheses in formal terms and layperson's terms for the t test for independent samples

2. Do the math and reject or accept at a=.05

3. Explain the results in layperson's terms

4. Calculate and explain a 95% confidence interval in layperson's terms if appropriate.

The library thinks the average number of patrons for 12-9 PM hours is 60. Use the data for 12-9 from the previous question

1. Provide the null and alternative hypotheses formal and layperson’s informal terms for a t one-sample test.

2. Do the math and reject or accept at a=0.05

3. Explain the results in layperson’s terms

An engineer at a microcircuit factory will inspect a batch of silicon wafers to try to find defects. Assume that there are four defective integrated circuits in a container containing twenty wafers. For that inspection two random wafers are selected. Calculate the probability that:
a) None of them have defects
b) At least one of the two has no defects.