Known: Traffic averages 1825VPH

Standard deviation pf 375VPH

Sample of 20 days

A) Use a t distribution to determine the probability of traffic exceeding 2200 VPH and

B) Use a t distribution to determine the t value for where t <0.02 (2%).

A diet doctor claims Australians are, on average, overweight by more than 10kg. To test this claim, a random sample of 100 Australians were weighed, and the difference between their actual weight and their ideal weight was calculated and recorded.

The data are contained in the Excel file Weights.xlsx.

Use these data to test the doctor's claim at the 5% level of significance.

Question 10

(Part B)

In this question, we let μ represent

Question 11

(Part B)

The null hypothesis is

Question 12

(Part B)

The alternative hypothesis is

Question 13

(Part B)

The value of the t-statistic is

Question 14

(Part B)

The decision rule is

Question 15

(Part B)

The p-value is

Let U and V be independent continuous random variables uniformly distributed from 0 to 1. Let X = max(U, V). What is Cov(X, U)?

Question is based on the information given below: Annual Cancer Death in White Male Workers in Two Industries Industry A Industry B No. of Deaths % of All Cancer Deaths No. of Deaths % of All Cancer Deaths Respiratory system 180 33 248 45 Digestive system 160 29 160 29 Genitourinary 80 15 82 15 All other sites 130 23 60 11 Total 550 100 550 100 Based on the preceding information, it was concluded that workers in industry B are at higher risk of death from respiratory system cancer than workers in industry A. (Assume that the age distributions of the workers in the two industries are nearly identical.) 1. Which of the following statements is true? The conclusion reached in correct The conclusion reached may be incorrect because proportionate mortality rates were used when age-specific mortality rates were needed The conclusion reached may be incorrect because there was no comparison group The conclusion reach may be incorrect because proportionate mortality was used when cause-specific mortality rates were needed. None of the above

The mortality rate from disease X in city A is 75/100,000 in persons 65 to 69 years old. The mortality rate from the same disease in city B is 150/100,000in persons 65-69 years old. The inference that disease X is two times more prevalent in persons 65 to 69 years old in city B than it is in persons 65-69 years old in city A is: Correct Incorrect, because of failure to distinguish between prevalence and mortality Incorrect, because of failure to adjust for differences in age distributions Incorrect, because of failure to distinguish between period and point prevalence Incorrect, because a proportion is used when a rate is required to support the inference

Height Requirement Assignment

Use the given parameters to complete the assignment:

• Men's heights are normally distributed with mean 69.5 in. and standard deviation 2.4 inches.
• Women's heights are normally distributed with mean 63.8 in. and standard deviation 2.6 inches.

The U.S. Air Force requires pilots to have heights between 64 in. and 77 in.

Answer the following questions for the height requirement for U.S. Air Force pilots.

a) What percent of women meet the height requirements?
b) What percent of men meet the height requirements?
c) If the Air Force height requirements are changed to exclude only the tallest 5% of men and the shortest 5% of women, what are the new height requirements?

1. A study was conducted of recent high school graduates who began full-time jobs rather than going to college. We wish to find the average starting income µ of such workers. A random sample of size 60 gave a sample mean of $24,500 with a population standard deviation of $2350.Round answers to 2 decimal places.

1. Find the standard error.

2. Identify the upper and lower z score for a 95% confidence interval for µ.

3. Calculate the upper and lower bounds of the confidence interval.

1. A study was conducted of recent high school graduates who began full-time jobs rather than going to college. We wish to find the average starting income µ of such workers. A random sample of size 60 gave a sample mean of $24,500 with a population standard deviation of $2350.Round answers to 2 decimal places.

1. Find the standard error.

2. Identify the upper and lower z score for a 95% confidence interval for µ.

3. Calculate the upper and lower bounds of the confidence interval.

Answer following:

1. After several studies, professor smith concludes that there is a zero correlation between body weight and bad tempers. This means that

2. A traffic safety officer conducted an experiment to determine whether there is a correlation between people's ages and driving were randomly sampled and the following data were collected.

Age: 20 25 45 46 60 65

Speed: 60 47 55 38 45 35

The value of pearson r equals

3. If sy=1, and sx=1, and r=0.6, what will the value of b be?

4. Correlation is the same thing as causation = t/f

5. A researcher collects data on the relationship between the amount of daily exercise an individual gets and the percent of body fat following scores were recorded.

Exercise (minutes): 10 18 26 33 44

% Body Fat: 30 25 18 17 14

Assuming the linear relationship holds, the least square regression line for predicting % body fat from the amount of exercise ___

6. What is the probability of rolling two sixes with one roll of a pair of dice ( a six and a six)? =

7. In a positive relationship, =

8. If the regression equation for a data set is Y'=2.650X+11.250, then the value of Y' for X=33 is =

9. Suppose you are going to randomly order individuals A,B,C,D,E, and F. the probability that the first person will be A and the second person will be B is =

10. The probability of drawing an ace followed by a king (without replacement) equals =

Suppose systolic blood pressure of 17-year-old females is approximately normally distributed with a mean of 113 mmHg and a standard deviation of 24.71 mmHg. If a random sample of 22 girls were selected from the population, find the following probabilities:

a) The mean systolic blood pressure will be below 109 mmHg. probability =

b) The mean systolic blood pressure will be above 118 mmHg. probability =

c) The mean systolic blood pressure will be between 106 and 125 mmHg. probability =

d) The mean systolic blood pressure will be between 106 and 113 mmHg. probability =

For each of the following questions, determine which kind of prediction confidence interval is appropriate.

a). Predict the humidity level in this greenhouse tomorrow when we set the temperature level at 31 °C?

b). Predict how much do families spend, on the average, on meals? Suppose the family income is $50,000

c). Predict how many kilowatt-hours of electricity will be consumed in September by commercial and industrial users in the Twin Cities service area, given that the index of business activity for area remains at the level of August?

d). Predict how many kilowatt-hours of electricity will be consumed daily on average in September (30 days) by commercial and industrial users in the Twin Cities service area, given that the index of business activity for area remains at the level of August 31?

a. Why is a random sample typically not collected? Develop a research question and determine how we would need to organize the study to use random sampling.

b. Imagine that you flip a coin 50 times. How would you use the terms trial, outcome, and success to describe this task?

c. What is the difference between the null hypothesis and the research, or alternative, hypothesis? Why do we never accept the null hypothesis or the research hypothesis?

d. What are Type I and Type II errors, and why are Type I errors considered to be particularly detrimental to research?

Answer true or false with a sentence or two explanation.

1. In order to construct a confidence interval estimate of the population mean, the value of the population mean is needed.

2. A confidence interval is an interval estimate for which there is a specified degree of certainty that the actual value of the population parameter will fall within the interval.

3. The larger the confidence level used in constructing a confidence interval estimate of the population mean, the narrower the confidence interval.

4. The term 1 – alpha refers to the probability that a confidence interval does not contain the population parameter.

5. In the formula , Xbar plus or minus z alpha / 2 times the stand dev. / sq root of n. the subscript alpha over 2 refers to the area in the lower tail or upper tail of the sampling distribution of the sample mean.

6. When constructing confidence interval for a parameter, we generally set the confidence level 1 - alpha close to 1 (usually between 0.90 and 0.99) because it is the probability that the interval includes the actual value of the population parameter.

7. Suppose that a 90% confidence interval for Mu is given by Xbar plus or minus .75. This notation means that we are 90% confident that Mu falls between xbar minus .75 and xbar plus .75

8. When a sample standard deviation is used to estimate a population standard deviation, the margin of error is computed by using the standard normal distribution.

9. The width of a confidence interval is independent of the sample size.

10. Suppose a sample size of 5 has mean 9.60. If the population variance is 5 and the population is normally distributed, the lower limit for a 92% confidence interval is 7.85.

Problem 1. When Abe graduated from Texas A&M, he bought a diamond ring with a golden insignia to impress his high school friends. The person most impressed was his old sweetheart, Beth. They grew so fond of each other that Abe asked Beth to wear his ring. Then the quarreling began. The relationship deteriorated until, in a fit of anger, Beth enrolled as a student at University of Texas. Abe, naturally, broke off the relationship and asked for the return of his ring. Beth replied that it was a gift to her and she was not about to return it. He answered that he had only loaned it to her to wear for the duration of their friendship. Abe and Beth are now involved in a legal dispute over the ring. Beth possesses the ring and she declares that she intends to sell it. Abe threatens to sue her. If Abe wins at trial, the court will require Beth to return the ring to him. The ring is worth $1,000 to Abe. If Beth wins at trial, the court will allow her to keep the ring. She would then sell the ring for $600 to an acquaintance. (The acquaintance does not know Abe and will not resell the ring to him.) In the event of a trial, each one expects to win with probability 0.5. A trial will cost Abe $250 and it will also cost Beth $250. Abe and Beth start negotiating to reach a settlement and avoid a trial. The costs of settling out of court are nil. Assume that these numbers are common knowledge for all parties.

Abe's expected value from going to trial is:

Beth's expected value from going to trial is:

The bargaining surplus over which the two are negotiating is:

If Abe and Beth were to split the bargaining surplus evenly, what kind of exchange (ring and currency) should take place?

A) Abe should let Beth keep the ring in exchange of her giving him $200.

B) Beth should give Abe the ring in exchange of him giving her $600.

C) Beth should give Abe the ring in exchange of him giving her $400.

D) Beth should give Abe the ring in exchange of him giving her $250.

E) Abe should let Beth keep the ring in exchange of her giving him $1000.