The time needed to complete a final examination in a particular college course is normally distributed with a mean of 100 minutes and a standard deviation of 20 minutes. Answer the following questions.

(a)What is the probability of completing the exam in one hour or less?

(b) What is the probability that a student will complete the exam in more than 60 minutes but less than 75 minutes?

(c) Assume that the class has 90 students and that the examination period is 130 minutes in length. How many students do you expect will be unable to complete the exam in the allotted time

QUESTION 17 If a sample average is found to be 62.7, and the margin of error is calculated to be 4.6, then the upper end of the confidence interval for mu would be ______

QUESTION 18 If a sample average is found to be 18, and the margin of error is calculated to be 0.06, then the lower end of the confidence interval for mu would be ______

QUESTION 19 Use your TI83 to find the upper end of the interval requested: A 95% confidence interval for the average height of the adult American male if a sample of 25 such males have an average height of 56.9 inches with a sample deviation of 3.4 inches. The population of all such heights is normally distributed round to the nearest hundredth of an inch

QUESTION 20 Use your TI83 to find the upper end of the interval requested: A 99% confidence interval for the average weight of a standard box of Frosted Flakes if sample of 66 such boxes has an average weight of 16.8 ounces with a population deviation of 0.4 ounces round to the nearest hundredth of an ounce

Jake Yum's new computer program "Learn to be a Great Cook" is selling off the shelves, and Jake wants to know whether there is a gender difference in the cooking quality of individuals who use the software. So Jake asked 10 males and 20 females to spend 20 hours over a month to go through the program. Jake then asked each participant to cook a dinner for him that includes a meat, 2 veggies, a bread, a dessert, and an appropriate wine. All meals were subsequently ranked, and the sum of ranks for males equaled 80, while the sum of ranks for females equaled 385. Use a Mann-Whitney U test, an alpha of .05, and two tailed. (Note: include hypotheses, detailed calculations, critical value, and outcome statement in sentence form).

In the box below, provide the following information:

Null Hypothesis in sentence form (1 point):

Alternative Hypothesis in sentence form (1 point):  
Critical Value(s) (2 points):

Calculations (4 points): Note: the more detail you provide, the more partial credit that I can give you if you make a mistake.

Outcome (determination of significance or not, effect size if appropriate, and what this reflects in everyday language, 2 points)

Case Study 3: Credit Data, Inc. Credit Data, Inc., has been monitoring the amount of time its bill collectors spend on calls that produce contacts with consumers. Management is interested in the distribution of time a collector spends on each call in which they initiate contact, inform a consumer about an outstanding debt, discuss a payment plan, and receive payments by phone. Credit Data is mostly interested in how quickly a collector can initiate and end a conversation to move on to the next call. For employees of Credit Data, time is money in the sense that one account may require one call and 2 minutes to collect, whereas another account may take five calls and 1 0 minutes per call to collect. The company has discovered that the time collectors spend talking to consumers about accounts is approximated by a normal distribution with a mean of 8 minutes and a standard deviation of 2.5 minutes. The managers believe that the mean is too high and should be reduced by more efficient phone call methods. Specifically, they wish to have no more than 1 0% of all calls require more than 1 0.5 minutes. Questions: Assuming that training can affect the average time but not the standard deviation, the managers are interested in knowing to what level the mean call time needs to be reduced in order to meet the 1 0% requirement. Assuming that the standard deviation can be affected by training but the mean time will remain at 8 minutes, to what level must the standard deviation be reduced i order to meet the 1 0% requirement? If nothing is done, what percent of all calls can be expected to require more than 10.5 minutes?

WRITE

Brief Introduction

• Research methodology

• Research findings, discussion and conclusion

• Appendix contains the output used in your research

• With normal distribution sketch the graph and shade the region

Prove that through a point P there are exactly 3 lines parallel to p, the polar of P.

A researcher is interested in whether the likeability of a crying woman is affected by the viewer’s knowledge of the woman’s occupation. Twenty participants were shown a video of a woman crying and were asked to rate her likeability on a scale from 1 (not very likable) to 10 (highly likable). Prior to viewing the video, participants were told that the woman was either a lawyer, a nurse, a teacher, or they were not told anything about her occupation (control condition).

(a) State the null and research hypotheses. (b) Calculate the appropriate test statistic. (c) Interpret the test statistics at an alpha level of .05.

**Please show all work and explain!! Thank you!!

A researcher studied the effects of three experimental diets with varying fat contents on

the total lipid (fat) level in plasma. Total lipid level is a widely used predictor of coronary heart disease.

Fifteen male subjects who were within 20 percent of their ideal body weight were grouped into five

blocks according to age. Within each block, the three experimental diets were randomly assigned to the

three subjects. Data on reduction in lipid level (in grams per liter) after the subjects were on the diet for

a fixed period of time follow.

Fat Content of Diet

How would I obtain an analysis of variance table and test whether or not the mean reductions in lipid levels differ for the three diets using alpha(a = .05)?

   1.   Suppose that cans of creamed corn are produced in a normal distribution so that the average net content weight is 16.00 ounces per can, with a deviation of 0.12 ounces. What is the probability that a sample of 36 cans would have an average net content weight less than 15.91 ounces? Would this be an unusual or not unusal average weight for the sample?

.

2.   Suppose that cans of creamed corn are produced in a normal distribution so that the average net content weight is 16.00 ounces per can, with a deviation of 0.12 ounces. What is the third quintile for sample averages from  samples of 36 cans? (nearest thousandth)

3.   Suppose a 98% confidence interval is needed for the average weight of these cans of creamed corn is needed, because someone thinks the average is not the 16 ounces it was supposed to be. If this interval is to have a margin of error of  0.02 oz, how many data points will be needed for the new sample?

4.   Suppose that cans of creamed corn were supposed to be  produced so that the average net content weight is 16.00 ounces per can. However, a sample of 64 weights yields an average of 15. 953 ounces and a deviation of 0.0762 ounces. Use this sample information to create a 98% confidence interval for the population mean (round to the nearest thousandth of an ounce)

Can a six-month exercise program increase the total body bone mineral content (TBBMC) of young women?
That is, we are interested in determining if the exercise program is beneficial, i.e., the mean percent change is positive.

Assume a sample of 25 subjects is taken.

A team of researchers is planning a study to examine this question.
Based on the results, they are willing to assume that σ = 2 for the percent change in TBBMC over the six- month period.
They also believe that a change in TBBMC of 1% is important, so they would like to have a reasonable chance of detecting a change this large or larger.

Calculate the power of this test.

Use the step by step procedures: Social scientists have long been interested in the relationship between economic development and health. To gain some insight into this relationship, we can utilize data on the life expectancy of females from birth and GDP per capita. you’ll find data from 91 countries. Use the data in the sheet entitled “Part 2 Question 9” to calculate and interpret the correlation coefficient.

(1) Using a similar dataset in “Part 2 Question 10”, calculate and interpret the correlation coefficient for the data on a life expectancy of males from birth and GDP per capita.

1) Design a study that uses a dependent samples design

2) Design a study that uses an independent samples design. Be sure to make clear your independent and dependent variables.

Base your two studies on the same general idea.

B. In a test of the effect of dampness on electric connections, 100 electric connections were tested under damp conditions and 150 were tested under dry conditions. Twenty of the damp connections failed and only 10 of the dry ones failed.

(i) Conduct a hypothesis test with α = 0.10 to determine whether or not there is a greater proportion of connections which fail under damp conditions compared to dry conditions. Be sure to state your hypotheses, test statistic, p-value, and conclusions.

(ii) Construct a 90% two-sided confidence interval for the difference of proportions πdamp −πdry. Compare the CI with the results of the hypothesis test in (i). Are the conclusions consistent?

This question is modified from an actual experiment published in a medical journal. A study claimed that people who eat high-fibre cereal for breakfast will on average consume fewer calories for lunch than people who do not eat high-fibre cereal for breakfast. A group of 150 people were randomly selected. Each person was identified as either a consumer or a non-consumer of high-fibre cereal at breakfast, and the number of calories consumed at lunch was measured and recorded. Here are the data. (Numbers are fictitious.)
(a) Calories consumed at lunch by high-fibre breakfast consumers:

568 646 607 555 530 714 593 647 650 498 636 529 565 566 639 551 580 629
589 739 637 568 687 693 683 532 651 681 539 617 584 694 556 667 467 540

596 633 607 566 473 649 622

(b) Calories consumed at lunch by low-fibre breakfast consumers:
705 754 740 569 593 637 563 421 514 536
819 741 688 547 723 553 733 812 580 833
706 628 539 710 730 620 664 547 624 644
509 537 725 679 701 679 625 643 566 594
613 748 711 674 672 599 655 693 709 596
582 663 607 505 685 566 466 624 518 750
601 526 816 527 800 484 462 549 554 582
608 541 426 679 663739 603 726 623 788
787 462 773 830 369 717 646 645 747
573 719 480 602 596 642 588 794 583
428 754 632 765 758 663 476 490 573
Test if the result of the study is statistically significant at 5% significance level. (COULD YOU PLEASE DESCRIBE ALL THE STEPS ONE BY ONE IN YOUR CALCULATION?) Thank you in advance for your help.

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The U.S. Bureau of Mines produces data on the price of Minerals. The data below displays the average prices per year for several minerals over a decade.

Use the attached MS Excel spreadsheet data and multiple regression to produce a model to predict the average price of gold from other variables. Comment on the following:

1. Regression equation
2. R, R2 and 1-R2, adjusted R2
3. Standard error of estimate
4. Report the t's for each value and the corresponding p-values
5. Overall test of hypothesis and decision
6. Use a .05 level of significance. Cite which variables are significant and which are not significant, based on the t values and p values for each independent variable.

A store sold 12 stereos on Monday, 17 on Tuesday, 28 on Wednesday, 17 on Thursday and 26 on Friday. AT the .01 level, test if there is a difference in the number of stereos sold on each weekday. State the hypotheses and identify the claim, find the critical value(s), compute the test value, make the decision and summarize the results. Show all work and formulas - sample question that I don't get.