To test whether students in a higher grade level will be less disruptive in class, a school psychologist records the number of documented interruptions during one day of classes from nine local high schools. The sample consisted of nine

(n = 9)

freshman, sophomore, junior, and senior high school classes. The data for each high school class are given in the table.

(a) Complete the F-table. (Round your answers to two decimal places.)

(b) Is it necessary to compute a post hoc test? Explain. (Assume alpha equal to 0.05.)

Yes, post hoc analyses are appropriate because the ANOVA is significant.

No, post hoc analyses are not appropriate because the ANOVA is not significant.    

You may need to use the appropriate table in Appendix B to answer this question.

Motor-Dexterity Test Motor-dexterity tests are often used in psychological studies, especially in neuropsychology. For this task, we are going to test motor-dexterity while looking for signs of frustration. First, take a clean pair of rolled-up socks or some other soft item. Then, have the participants throw it into a hoop you make with your arms. The objective is not to see how well they do the task but to see which hand they use; you are trying to determine dominance. After doing this task, ask the participants which hand they prefer to use when writing. While most will prefer the right, some will prefer the left. If a person says both, ask that individual to write a sentence with both hands, one at a time and the two of you can decide which hand to call dominant. In most cases, people will report they use the right hand more, and they will also unintentionally pick the right hand to throw the object with. If they report left and use the right hand to throw, then record that as mixed, but select the hand they choose as dominant. In the end, you will go with what the participant decides. You are required to record all information on the data sheet. This study involved ten participants. The researcher timed how fast each person put fifteen toothpicks into a mug with each hand. To reduce a significant difference being caused by practice effects, five of the participants started with their dominant hand (DH) and the next set of five started with their nondominant hand (NDH). While they were doing the task, the researcher rated the level of frustration while performing with one hand and then the other one. The researcher was careful not to allow experimenter bias to influence what he or she recorded. Here is the scale used to rate frustration: Very Frustrated Not Very Frustrated 5 4 3 2 1 Look at the data sheet: Participant # Start with NDH (seconds) FL-NDH DH (seconds) FL-DH 1 Right 7 3 6 1 2 Right 10 4 8 2 3 Right 9 3 8 2 4 Left 6 2 7 3 5 Right 8 4 6 1 6 Left 12 5 9 1 7 Left 8 1 7 1 8 Right 11 3 10 2 9 Left 8 2 8 2 10 Left 13 5 9 3 The hypotheses for the study were: People will perform the motor-dexterity task faster with their DH as compared to their NDH. People will show more frustration while using the NDH. Determine the average time with the motor-dexterity test, along with the standard deviation, and then use Minitab to analyze the data with a paired t-test to see if there is a significant performance difference between the two hands. Run another paired t-test to see if there is a difference in frustration (FL) while using the DH versus the NDH. Obtain the results and decide if the hypotheses are supported. Write a summary of the findings. Submit the results and summary of the findings in a 3- to 4-page Microsoft Word document.

Iconic memory is a type of memory that holds visual information for about half a second (0.5 seconds). To demonstrate this type of memory, participants were shown three rows of four letters for 50 milliseconds. They were then asked to recall as many letters as possible, with a 0-, 0.5-, or 1.0-second delay before responding. Researchers hypothesized that longer delays would result in poorer recall. The number of letters correctly recalled is given in the table.

(a) Complete the F-table. (Round your values for MS and F to two decimal places.)

(b) Compute Tukey's HSD post hoc test and interpret the results. (Assume alpha equal to 0.05. Round your answer to two decimal places.)

The critical value is_____ for each pairwise comparison.

Which of the comparisons had significant differences? (Select all that apply.)

-Recall following no delay was significantly different from recall following a half second delay.

-The null hypothesis of no difference should be retained because none of the pairwise comparisons demonstrate a significant difference.

-Recall following a half second delay was significantly different from recall following a one second delay.

-Recall following no delay was significantly different from recall following a one second delay.

Consider the following price data from 2002 to 2010

a. Compute the simple price index using 2002 as the base year. (Round your answers to 2 decimal places.)

b. Update the index numbers with a base year revised from 2002 to 2005. (Round your answers to 2 decimal places.)

A survey was conducted among 92 men and 217 women and got their BMI values. Among the 92 men, the average BMI is 24.4 with standard deviation 3.4. Among the 217 women, the average BMI is 22.3 and standard deviation is 3.6.

(1) Assuming that BMI follows a normal distribution, please calculate what values of BMI that the 95% of men and women will have. In other words, 95% of men and women’s BMI will be within what range. Please calculate for men and women separately. (4 points)

(2) Assume that women’s BMI follows a normal distribution with the population mean as 22 and standard deviation as 3, please calculate the probability of a woman with BMI < 25, between 25 –29.9, and 30 or more. (6 points)

(3) Assuming that BMI follows a normal distribution, using the sample mean, standard deviation and sample size from the sample to calculate the 95% confidence interval for men and women’s BMI separately. In other words, 95% of sample means of men and women’s BMI will be within what range. Please calculate for men and women separately. (4 points)

Using the information from above, with p′=0.714, q′=0.286, and n=140, what is the 90% confidence interval for the proportion of the population who use public transportation?

Use the table of common z-scores above.

• Round the final answer to three decimal places.
• 90% of the X-values lies between ____ and _____

The Herald marketing department is seeking to increase home-delivery sales through an aggressive direct-marketing campaign that includes mailings, discount coupons, and telephone solicitations. Feedback from these efforts indicates that getting their newspapers delivered early in the morning is a very important factor for both prospective and existing subscribers. After several brainstorming sessions, a team consisting of members from the marketing and circulation departments decided that guaranteeing newspaper delivery by a specific time could be an important selling point in retaining and getting new subscribers. The team concluded that the Herald should offer a guarantee that customers will receive their newspaper by a certain time or else that day’s issue is free. To assist the team in setting a guaranteed delivery time, Al Leslie, the research director, determined that the circulation department had data that showed the percentage of newspapers yet undelivered every quarter hour from 6AM to 8AM. Jan Shapiro remembered that customers were asked on their subscription forms at what time they would be looking for their copy of the newspaper to be delivered. These data were subsequently combined and are available below. Your job is to review the internal data and propose a reasonable time (to the nearest quarter hour) to guarantee delivery. To help explore the effects of your choice, calculate the following probability: If a sample of 50 customers is selected on a given day, what is the probability, given your selected delivery time, that a. Fewer than 3 customers will receive a free newspaper? b. 2, 3, or 4 customers will receive a free newspaper? c. More than 5 customers will receive a few newspaper? Use the binomial distribution function in excel to perform required calculations.

If you draw a card with a value of three or less from a standard deck of cards, I will pay you $47. If not, you pay me $12. (Aces are considered the highest card in the deck.)

)  

Find the expected value of the proposition. Round your answer to two decimal places. Losses must be expressed as negative values

Question 3: Consider the contingency table from Question 2.

Post-flight respiratory problem? Yes
No

Re-circulate Air (RA) 110
405

Do not re-circulate air (RAc) 108
477

A passenger just gets of a flight from San Francisco to Denver. What is the probability

1. (a) What is the probability that they flew on (i) on a plane that re-circulated the air? (ii) will have post-flight respiratory problems?

2. (b) he/she will have flown on a plane with re-circulated air or will experience post-flight respiratory prob- lems?

3. (c) If he/she experienced post-flight respiratory problems, what is the probability they flew on a plane where the air was not re-circulated?

4. (d) Are the events ‘RA’ and experiencing ‘post-flight respiratory problems mutually exclusive events? Independent events?

Question 2: The Journal of the American Medical Association reported in 2002 on a study of 1,100 airline passengers who flew from San Francisco to Denver. 515 of these passengers traveled on planes where air was re-circulated, the remaining 585 traveled on planes that did not recirculate air. Of those that did travel on planes where the air was recirculated, 110 reported post-flight respiratory problems. Of those on planes that did not recirculate the air, 108 reported post-flight respiratory problems.

1. (a) Is there a difference in the proportion of passengers who experience post-flight respiratory problems between planes who re-circulate air and planes that do not? State the statistical hypotheses.

2. (b) Carry out the statistical test at a level of significance of 5%.

3. (c) What can you conclude?

4. (d) Interpret the meaning of the P -value you computed, in the context of the data.
   Should you reject the null hypothesis in part (a), compute the 95% confidence interval for the difference in the proportion of passengers experiencing post-flight respiratory problems in planes that recirculate air and planes that do not, pReCirculate − pNoRecirculate.

You will perform an ANOVA test. For the hypothesis test make sure to report the following steps:

1. Identify the null hypothesis, Ho, and the alternative hypothesis, Ha.
2. Determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed.
3. Find the critical value(s) and identify the rejection region(s).
4. Find the appropriate standardized test statistic. If convenient, use technology.
5. Decide whether to reject or fail to reject the null hypothesis.
6. Interpret the decision in the context of the original claim.

The grade point averages of students participating in sports at a local college are to be compared. The data are listed below. Test the claim that at least one group has a different mean. Use α = 0.05.

A sociologist claims that sleeping time of children ages 12-14 in 1981 is different from that of children ages 12-14 today. A study was conducted in 1981 to find the time that children ages 12-14 with samplse size of 22. Recently, similar study was conducted with sample size of 20. Summary of the sleep time comarison is given below. Use α = 0.01 to perform the analysis.

  data:  sleep_1981 and sleep_now
  t = -8.7477,  p-value = ......
  alternative hypothesis: true difference in means is not equal to 0
  99 percent confidence interval:

   -1.6238202 -0.8561798
  sample estimates:
  mean sleep time 1981 mean sleep time recently

7.75 8.99

1. (a) Which test is reasonable to use? Indepenpaired t-test or paired t-test? Defend your choice.

2. (b) State the null and alternative hypothesis.

3. (c) Circle one: One Tail Test / Two Tail Test.

4. (d) Illustrate graphically the rejection region.

5. (e) Find the p-value for the test statistic. Use table.

   (f) Give the significant statement for the hypothesis test. Make sure to connect your result with the story of question for full credit.

   (g) Find 99% confidence interval and interpret it in the context of the question. Pay extra attention to the signs of lower and upper limits of confidence interval. Does it reveal more about the comparisons of these data?

The following data shows the hours worked by employees at a McDonalds and the number of dollars that they earned that day. Hours worked Pay dollars 8 68 7 59.5 8 68 5 42.5 10 85 8.5 72.25 7.5 63.75 9 76.5 Average: 7.875 66.9375 Standard Deviation 1.482035 12.5973 Correlation 1 a)Draw a scatterplot that represents this data. Draw an estimate for the line of least fit on the scatterplot as well. b) Use technology to find the least squares regression line. Write the equation below. c) Use the equation from the previous question to find how much a person would be paid for a 12 hour shift. Show your work.

For the question as followed, just write the formula and the way you solve the problem:

1.

Given a chart a, size = 50 (i.e. 50 values in chart a), and the range of the chart a is given

Divide the range into N = 10 equal-length segments (hereafter called “bins”) and for each bin, find its bound (aj , bj ) as well as its center cj for j = 1, 2,..., 10.

2.

Sort the data and place each value "ai" into that bin whose lower bound is less than or equal to "ai" and whose upper bound is greater than "ai"; thereafter, for each bin count the number of "ai" assigned to the new declare variable.