A local university wants to conduct a sample of 200 students out of 6000 students. We can assume that the university maintains a good roster of all registered students. (1) how would you select the 200 students(a) using simple random sample method and (b) systematic sampling method? (2) suppose that the university administration wants to make sure in particular students who major in music (a small department with only 8% of students major in music)be adequately included in your sample, how would you go about selecting a sample ?

The conference Board produces a Consumer Confidence Index (CCI) that reflects people's feelings about general business conditions, employment opportunities, and their own income prospects. Some researchers may feel that consumer confidence is a function of the median household income.

Use the attached MS Excel spreadsheet containing the CCIs for nine years and the median household incomes for the same nine years published by the U.S. Census Bureau.

Perform a correlation and regression analysis to predict CCI using median household income. Discuss the following:

1. Scatter Diagram
2. R, R2 and 1-R2
3. The regression equation
4. Standard error of estimate
5. The test of hypothesis with the 5-step process. Use a .05 level of significance. Does median household income appear to be good predictor of the CCI? Why or why not?

A widget produced by a particular process has probability .1 of being defective. A test can be performed which has 99% accuracy. That is, if a defective widget is tested, the test will identify the widget as defective 99% of the time. And if a non-defective widget is tested, there is a 99% chance that the test will indicate that the widget is not defective. One widget is selected at random and is tested. If the test says that the widget is not defective, what is the probability that the widget actually is defective?

QUESTION 1

The fundalmental condition that permits proper statistical inference is

QUESTION 2

Randomization and random sampling

QUESTION 3

Randomization is used to

QUESTION 4

A population characteristic is known as a(n)

QUESTION 5

"statistic" is to "parameter" as

QUESTION 6

Whether or not a sample is considered random depends on

QUESTION 7

Each score in a random sampling distribution of means represents

QUESTION 8

Which of the following is a parameter?

QUESTION 9

The standard error of the mean

QUESTION 10

A sampling distribution is a distribution of

The equation of a regression line, unlike the correlation, depends on the units we use to measure the explanatory and response variables. Here is the data on percent body fat and preferred amount of salt. Preferred amount of salt x 0.2 0.3 0.4 0.5 0.6 0.8 1.1 Percent body fat y 19 31 22 29 39 24 31 In calculating the preferred amount of salt, the weight of the salt was in milligrams. (a) Find the equation of the regression line for predicting percent body fat from preferred amount of salt when weight is in milligrams. (Round your answers to one decimal place.) ŷ = + x (b) A mad scientist decides to measure weight in tenths of milligrams. The same data in these units are as follows. Preferred amount of salt x 2 3 4 5 6 8 11 Percent body fat y 19 31 22 29 39 24 31 Find the equation of the regression line for predicting percent body fat from preferred amount of salt when weight is in tenths of milligrams. (Round your intercept to one decimal place and your slope to two decimal places.) ŷ = + x (c) Use both lines to predict the percent body fat from preferred amount of salt for a child with preferred amount of salt 0.9 when weight is measured in milligrams, which is the same as 9 when weight is in tenths of milligrams. (Round your answers to one decimal place.) in milligrams % body fat in tenths of milligrams % body fat Are the two predictions the same (up to any roundoff error)? Yes No

A stationary store has decided to accept a large shipment of ballpoint pens if an inspection of 20 randomly selected pends yields no more than two defective pens. (a) Find the probability that this shipment is accepted if 5% of the total shipment is defective. (b) Find the probability that this shipment is not accepted if 15% of the total shipment is defective. Kindly use the numbers given in the word sentences to show the work. Thank you

This is observation from previous years about the impact of students working while they are enrolled in classes, due to students too much work, they are spending less time on their classes. First, the observer need to find out, on average, how many hours a week students are working. They know from previous studies that the standard deviation of this variable is about 5 hours. A survey of 200 students provides a sample mean of 7.10 hours worked. What is a 95% confidence interval based on this sample?

((NO HANDWRITING PLEASE))

College tuition:

The mean annual tuition and fees in the 2013 - 2014 academic year for a sample of 15 private colleges in California was 32,500 with a standard deviation of $7250. A dotplot shows that it is reasonable to assume that the population that the population is approximately normal. Can you conclude that the mean tuition and fees for private institutions in California is less than 35,000? Use a = 0.05 level of significance and the critical value method.

The hypothesis is a ... test.

In a random sample of five microwave​ ovens, the mean repair cost was $60.00 and the standard deviation was $11.50

Assume the population is normally distributed and use a​ t-distribution to construct a 90​% confidence interval for the population mean μ. What is the margin of error of μ​? Interpret the results.

(a)The confidence interval for the population mean is _, _   ​(Round to one decimal place as​ needed.)

(b)The margin of error is _ ​(Round to two decimal places as​ needed.)

(c) Interpret the results. Choose the correct answer below:

1. It can be said that 95​% of microwaves have a repair cost between the bounds of the confidence interval.

2.With 95​% confidence, it can be said that the population mean repair cost is between the bounds of the confidence interval.

3.With 95​% confidence, it can be said that the repair cost is between the bounds of the confidence interval.

4.If a large sample of microwaves are taken approximately 95​% of them will have repair costs between the bounds of the confidence interval.

In​ Louisiana, the average weight of an adult allegator is 790​ pounds, with standard deviation of 200 pounds. What is the probability that the average wieght of a sample​(of adults​ allegators) of size 100 will be grater than 820​ pounds?

A.0.06

B.0.07

C.0.93

D.0.90

E.0.05

A researcher conducts an independent-measures study examining the effectiveness of a group exercise program at an assisted living facility for elderly adults. One group of residents is selected to participate in the program, and a second group serves as a control. After 6 weeks, the researcher assessed physical fitness of each participant.

The data are as follows: Exercise Group: Control Group: n = 15 n = 15 M = 37 M = 34 SS = 230 SS = 160 A. Does the exercise program have a significant effect on physical fitness? Use p < .05, 2-tails test.

B. If there is a significant effect, compute the estimated Cohen’s d to measure the size of the treatment effect.

C. Write a conclusion demonstrating how the outcome of the hypothesis test and the measure of effect size would appear in a research report in APA style.

Note: For full credit show all steps of hypothesis testing (i.e., write hypotheses, all computations, the tcritical used for the decision about H0 and the conclusion in APA reporting format).

In a random sample of 23 people, the mean commute time to work was 30.3 minutes and the standard deviation was 7.1 minutes. Assume the population is normally distributed and use a​ t-distribution to construct a 98​% confidence interval for the population mean .What is the margin of error of f μ​? Interpret the results.

(a)The confidence interval for the population mean is _, _   ​(Round to one decimal place as​ needed.)

(b)The margin of error is _ ​(Round to two decimal places as​ needed.)

(c) Interpret the results. Choose the correct answer below:

1. It can be said that 95​% is between the bounds of the confidence interval.

2.With 95​% confidence, it can be said that the population mean is between the bounds of the confidence interval.

3.With 95​% confidence, it can be said that is between the bounds of the confidence interval.

4.If a large sample is taken approximately 95​% of them are between the bounds of the confidence interval.

If n=20, ¯ x (x-bar)=36, and s=13, construct a confidence interval at a 99% confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place.