1. Asimplerandomsampleof1000graduates ofauniversityshowedthat54%earnatleast

$40,000peryear.Constructa95% confidence interval estimate for p = the percentage of university graduates who earn at least $40,000 per year.

a) $39,685to $40,315

b)52.42% to 55.56%

c) 50.91%to 57.09%

d)Cannot be constructed from information given.

2. Todetectassociationbetweentherowandcolumn variablesofatwo-waytable, what do we examine?

1. Whethertheproportionsinthemarginal distributionofthecolumnvariable are decreasing, increasing, or staying constant.
2. Whethertheconditionaldistributioninarow(oracolumn)equalsthe conditional distributions of all other rows (or columns).
3. Whetherthevalue ineachcelldividedbythetable totalequalsthevalueinthe row total divided by the table total.
4. Whether a lurking variable interacts with both the row and column variables.

Eighthundred studentsatalocaljunior collegewereasked iftheyfavored abanoncell phone usage in the school cafeteria.The results of the survey are as follows:

	Favor	Oppose	No	Opinion	Total
Males	153	176	71	400
Females	235	111	54	400
Total	388	287	125	800

3. Whatproportionofthestudents surveyedopposesabanoncellphone usageinthe school cafeteria?

a. 0.359

b. 0.383

c. 0.394

d. 0.485

e. 0.613

4. Refertotheabovetable. Whatproportionofthemales favorabanoncellphoneusage in the school cafeteria?

a. 0.359

b. 0.383

c. 0.394

d. 0.485

e. 0.613

5. Refertotheabovetable.Whatistheconditionaldistributionofopinionformales? a.38.3%, 44.0%, 17.8%

b.39.4%, 61.3%, 56.8%

c. 58.8%,27.8%, 13.5%

d. 60.6%, 38.7%, 43.2%

6. Aschool districtwonderediftheaverage scoreoftheir studentsintheMathSATexam differed from the national average of 450.A random sample of 30 seniors from the district had a mean of 486 with a sample standard deviation of 85.What is the P-value

forthetestofH0:=450versusH1450?

1. 0.01 < P< 0.02 from the t table
2. 0.02 < P< 0.04 from the t table
3. 0.0104 from the z table
4. 0.0208 from the z table

7. The numbers in Table B (the random number table) have a mean of 4.5 and a standard deviationof2.87.Ifyouweretotakeasimple randomsampleof32numbers intableB by placing your finger at a random spot and taking the next 32 numbers, what is the probability that yourxvalue would be greater than 5?

a. 0.0145

b. 0.1611

c. 0.5073

d. 0.4927

8. A quality inspector checks a large truckload of potatoes to determine the proportion of defective potatoes.She tests the hypothesesH₀: p= 0.06versusH_a: p> 0.06and will accept the shipment unless she has sufficient evidence that the proportion of defective potatoes significantly exceeds 6%.She plans to randomly sample 100 potatoes.Is this sample size large enough to perform a one-sample z test for the proportion?

a. Yes, because n> 40.

b. Yes, because there are no outliers or strong skewness in categorical data.

c. No,because 100(.06) < 10.

d. There is not enough information to check whether the sample size is large enough.

9. Referring to question 18, assume that the quality inspector takes a random sample of potatoesthatislargeenough tosatisfytheconditionsandfindsp-value=0.118.Should she accept the shipment at = 0.05?Why or why not?

1. No,becausewefail toreject H₀at =0.05.
2. NobecausewerejectH₀at=0.05.
3. Yes,becausewe fail toreject H₀at =0.05.
4. Yes,becausewereject H₀at=0.05.
5. Thereisnotenoughinformationtodeterminewhether sheshouldacceptthe shipment.

10. Inasimplerandom sampleofAmerican adults,10.6%of1067menwereleft-handedand 7.9% of 1170 women were left-handed.If the test statistic for investigating whether a greater percentage of men are left-handed than left-handed women in the whole population is z = 2.22, what is the p-value?

a.0.9869

b. 0.0132

c. 0.0222

d. 0.0264