The Business Education Department has six full-time faculty members. At their monthly department meeting, each full-time faculty member reported the number of hours they taught during the past month:

Faculty Member Teaching Hours

Bernhardt 84, Haas 92, England 84, Pecord 83, Hines 92, Tanner 83

A. Calculate the population mean for the six full-time faculty members:

B. If two full-time faculty members are selected randomly, how many different samples are possible?

C. Calculate the sample means:

D. Calculate the sampling distribution:

Can you provide an example of hypothesis testing in quantitative research and one in qualitative research?

1.  In a recent report released by Consumer Reports, it was reported that 7 in 10 auto accidents involve a single vehicle (thus, 3 out of 10 involve multiple vehicles). Suppose 15 accidents are randomly selected. Let x = the number of accidents involving a single vehicle.

a. What is the probability that less than 14 accidents involve a single vehicle?

b. What is the mean number of single vehicle accidents? What is the standard deviation?

c. What is the probability at least 2 accidents are multiple vehicle accidents?

Suppose you actually had 200 independent units in the sample and calculated the sample mean of 91.15g. The sample standard deviation is 0.9 grams. How many units from your new sample of 200 do you expect to lie in your 68% tolerance interval? Your 95% tolerance interval? Your 99.7% tolerance interval? Do not round any of your answers. Hint: Lecture 15 example 2 part d) should help you here.

Out of 480 respondents in a recent health survey 42 reported a history of diabetes.

a. Estimate the true proportion of people with a history of diabetes with 95% confidence.

b. Using the survey data above, what should the sample size be if the researchers wanted to be accurate to within 2% of the true proportion?

c. What should the sample size be if the researchers wanted to be accurate to within 2% of the true proportion, assuming they had no previous data?

1. . In a survey of 1000 American adults conducted in April 2012, 430 reported having gone through an entire week without paying for anything in cash. Test at 1% significance level to see if this sample provides evidence that the proportion of all American adults going a week without paying cash is greater than 40%.

(a) Define the parameter with proper notation. State the null and alternate hypothesis.

(b) Is it one or two tailed test? Give the direction if one tailed. What is the level of significance? Give the null value.

(c) Find the best point estimate rounded to three decimal places, with proper notation.

(d) If we were to draw a 1000 samples randomization distribution, each of size 1000, what is the expected shape and center of this randomization distribution?

(e) Draw a smooth curve of the randomization distribution and shade the area that represents the p- value for this sample.

(f) Using the following randomization distribution, find the p-value corresponding to the best point estimate. Describe the strength of the evidence based on this p-value (scale is 0.0067 units between each number).

(g) Based on the p-value what is the formal conclusion? What type of error is made? Describe what that type of error means in this situation.

(h) Based on the p-value, what is the conclusion in the context of the problem? (i) Find p-value for ?̂ = 0.45.

A paleontologist examines 39 skeletons of a new species of dinosaur and finds that the average length of the right femur is 90 cm, with a standard deviation of 9 cm.
a. Does this involve ?-values or ?-values? Explain how you know this.


b. Estimate the population mean with 95% confidence.

For each of the studies, please indicate the following:

1) Independent variable(s)

2) Number of IVs

3) The levels the independent variable(s)

4) Dependent variable

(for correlation, list all variables here)

5) Between (B/S) or within-subjects (W/S)?

6) What type of design is being used?

7) What is the appropriate statistic?

*If a question isn’t applicable to a particular design, please note that as well

Study1: A team of cognitive psychologists conducted a study on the effects of sleep deprivation on short-term memory decay. Forty-eight participants stayed in a lab for two days. Twenty-four of the participants are randomly assigned to a condition in which they are not permitted to sleep during that period. The other twenty-four are allowed to sleep whenever they want. At the end of the two days, the participants complete a task that involves reading a list of 20 words, then recalling as many words as possible.

Study2: A researcher examined the effect of different kinds of music on general math ability. Forty-eight participants were randomly assigned to do a series of math tasks under one of three conditions: 16 while listening to soft gentle music, 16 while listening to loud intense music, and 16 while in silence. The math quiz contained arithmetic, geometry, and word problems. There were 25 items that were 2 points each.

Study3: A health psychologist conducted a study on the how the number of hours a person exercised each week relates to the number of days being sick per year. Participants were randomly selected from the community and provided self-reports through a series of questions on the topics of interest.

Study4: A study was designed to test the effects of science fiction movies on participants' belief in the supernatural. A scale was designed to measure the degree that a participant believes in the supernatural on a 1-7 Likert Scale (high scores indicate high levels of belief). Fifty-seven participants, selected via random digit dialing (RDD) responded to the scale before and after watching Return of the Jedi, a popular science fiction movie.

Study5: A researcher at a drug treatment center wanted to determine the best combination of treatments that would lead to more substance free days. This researcher believed there were two key factors in helping drug addiction: type of treatment and type of counseling. The researcher was interested in either residential or outpatient treatment programs and either cognitive-behavioral, psychodynamic, or client-centered counseling approaches. As new clients enrolled at the center they were randomly assigned to one of six experimental groups. After 3 months of treatment, each client’s symptoms were measured.

Study6: An organizational psychologist is hired as a consultant by a person planning to open a coffee house for college students. The coffee house owner wants to know if her customers will drink more coffee depending on the ambience of the coffee house. To test this, the psychologist sets up three similar rooms, each with its own theme (Tropical; Old Library; or New York Café ) then arranges to have thirty students spend an afternoon in each room while being allowed to drink all the coffee they like. (The order in which they sit in the rooms is counterbalanced.) The amount each participant drinks is recorded for each of the three themes.

Study7: A manager at a retail store in the mall wants to increase profit. The manager wants to see if the store’s layout (one main circular path vs. a grid system of paths) influences how much money is spent depending on whether there is a sale. The belief is that when there is a sale customers like a grid layout, while customers prefer a circular layout when there is no sale. Over two days the manager alternates the store layout, and has the same group of customers come each day. Based on random assignment, half of the customers are told there is a sale (20 % will be taken off the final purchases), while the other half is told there is no sale. At the end of each day, the manager calculates the profit.

In his Ph.D. dissertation, Dr. Moser found the following variances in a population of yearling Brangus cattle measured for fat thickness with ultrasound:

                                    σ²_BV = .001 cm²          σ²_E = .009 cm²

            Assuming variance of gene combination value is zero, calculate:

                        a.         Phenotypic variance of fat thickness

                        b.         Heritability of fat thickness

Based on the above, is a yearling heifer’s fat thickness a good indicator of her breeding value for that trait? Why or why not?

In her Ph.D. dissertation, Dr. Bormann found the following variances for age at first calving in a population of Angus cattle:

                                    σ²_BV = 767 d²              σ²_E = 1395 d²

            Assuming variance of gene combination value is zero, calculate:

                        a.         Phenotypic variance of age at first calving

                        b.         Heritability of age at first calving

Based on the above, is a yearling heifer’s age at first calving a good indicator of her breeding value for that trait? Why or why not?

. All of the following are true of two-tailed tests except:

A. Two-tailed tests are more “conservative”, they make rejecting the null hypothesis harder


B. Two-tailed tests are used when there is not a clear basis for predicting a result in one specific direction

C. With a two-tailed test, your cutoff score will be more extreme than a one-tailed test

D. A two-tailed test improves the chances that you will get a statistically significant result

An amusement park studied methods for decreasing the waiting time (minutes) for rides by loading and unloading riders more efficiently. Two alternative loading/unloading methods have been proposed. To account for potential differences due to the type of ride and the possible interaction between the method of loading and unloading and the type of ride, a factorial experiment was designed. Use the following data to test for any significant effect due to the loading and unloading method, the type of ride, and interaction. Use . Factor A is method of loading and unloading; Factor B is the type of ride.

Set up the ANOVA table (to whole number, but -value to 2 decimals and  value to 1 decimal, if necessary).

The -value for Factor A is - Select your answer -less than .01between .01 and .025between .025 and .05between .05 and .10greater than .10Item 21

What is your conclusion with respect to Factor A?

- Select your answer -Factor A is significantFactor A is not significantItem 22

The -value for Factor B is - Select your answer -less than .01between .01 and .025between .025 and .05between .05 and .10greater than .10Item 23

What is your conclusion with respect to Factor B?

- Select your answer -Factor B is significantFactor B is not significantItem 24

The -value for the interaction of factors A and B is - Select your answer -less than .01between .01 and .025between .025 and .05between .05 and .10greater than .10Item 25

What is your conclusion with respect to the interaction of Factors A and B?

- Select your answer -The interaction of factors A and B is significantThe interaction of factors A and B is not significantItem 26

What is your recommendation to the amusement park?

- Select your answer -Use method 1; it has a lower sample mean waiting time and is the best methodWithhold judgment; take a larger sample before making a final decisionSince method is not a significant factor, use either loading and unloading methodItem 27

The customers association thought that the mean number of days for a package to arrive in Australia is more than 13 days. Assume that the population standard deviation is unknown. Does the sample data obtained provide evidence that the mean arrival time for packages is more than 13 days at the 5% level of significance? Use the p value approach. Show the Calculation steps by Excel. What formulas in statistics are used? Data of arrival time is given below.

Women have a mean systolic blood pressure of 125.17 with a standard deviation of 10.34. Female blood pressure is known to be normally distributed.
(a) Find the probability that a randomly selected female has a blood pressure below 110.

(b) What female systolic blood pressure represents the 99th percentile?




(c) A group of 45 women who take an allergy drug have a mean systolic blood pressure under 120. Should the drug company include a warning about users having lower systolic blood pressure? Justify your answer using probability.

The number of parking tickets issued in a certain city on any given weekday has a Poisson distribution with parameter μ = 40. (Round your answers to four decimal places.) (a) Calculate the approximate probability that between 35 and 70 tickets are given out on a particular day.

(b) Calculate the approximate probability that the total number of tickets given out during a 5-day week is between 195 and 265.

(c) Use software to obtain the exact probabilities in (a) and (b) and compare to their approximations. Calculate the exact probability that between 35 and 70 tickets are given out on a particular day. Calculate the exact probability that the total number of tickets given out during a 5-day week is between 195 and 265.

If np >= 5 and nq >= 5​, estimate Upper P( fewer than 6) with n =13 and p= 0.5 by using the normal distribution as an approximation to the binomial​ distribution; if np < 5 or nq < 5, then state that the normal approximation is not suitable.

P(fewer than 6) = ?