1) Choose the answer(s) that is (are) correct.

a) Increasing the confidence level increases the width of a confidence interval.

b) Decreasing the confidence level increases the width of a confidence interval.

c) A confidence interval with a 100% confidence level can be computed.

d) Decreasing sample size decreases the width of a confidence interval.

e) Increasing sample size decreases the width of a confidence interval

2) With 80% confidence, for sample proportion 0.46 and sample size 29, what is the upper confidence limit with 2 decimal places?

3) What is the margin of error for the population mean at 90% confidence level for the information in DATA below

a) 0.75

b) 0.74

C) 0.73

d) 0.72

e) None of the answers match my calculations

Data for question 3

Wait Time (minutes)

2.1

8.0

4.6

2.5

3.5

4.3

3.9

5.0

6.5

3.4

5.6

6.6

4.3

4.9

9.3

5.5

4.3

11.9

5.2

4.8

5.2

7.8

8.0

4.6

4.0

5.9

8.7

3.1

4.9

11.6

4) With 90% confidence, for sample mean 374.50, sample standard deviation 12.50, and sample size 35, what is the upper confidence limit with two decimal places

5) Match up the following:

Failure to reject H0 when H0 is false

Rejection of H0 when H0 is true

Rejection of H0 when H0 is false, or not rejecting H0 when H0 is true

The risk we are willing to take of a type 1 error, or the type 1 error rate

Match with these

Type 1 error. (1)

Type 2 error. ( 2)

Not an error.(3)

.(4)

(6) Match up the following:

The power of a test = P(rejecting H0|H0 false)

Test of this hypothesis requires 1-tailed test with upper reject region

Test of this hypothesis requires 2-tailed test with lower reject region bounded by negative critical value and upper reject region bounded by positive critical value

Reject H0

Test of this hypothesis requires 1-tailed test with lower reject region bounded by negative critical value

The probability of a type 2 error

Match with these

.(1)

1 - .(2)

pvalue < .(3)

H0: 0.(4)

H0: 0.(5)

H0: = 0.(6)

7) Match the rules for rejecting H0 at the right to the following tests

One-tail test with lower reject region

Two-tail test with lower and upper reject regions

One-tail test with upper reject region

For any test hypothesis, ANOVA, or Chi Squared, this rule for rejecting H0 always applies

Match with these

(1)test statistic > positive critical value.

(2) test statistic < negative critical value

(3)test statistic outside interval (negative critical value, positive critical value)

(4) pvalue <

Match problems to procedures.

Given weights of 31, 29, 26, 33, 40, 28, 30, and 25, at = 0.05 test that the population mean is 35.

Run times (msec) of a new phone app developed by GotYourGP and established competitor

WeTrackYou.Inc. are logged in a data file. At = 0.05, are the run times of GotYourGP and

WeTrackYou.Inc comparable?

Testing that a gasoline additive increases mileage, we compute mpg with additive minus mpg without additive for each car. If the mean of the differences is positive enough, action will be required to implement the additive.

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An effective vaccine would reduce the proportion of exposed persons contracting a disease. A pharmaceutical company wants to test the effectiveness of a new vaccine in preventing a certain disease. It is expected that 40% of unvaccinated exposed people will contract the disease. A group of 48 exposed persons volunteered to be vaccinated. Later, two of the volunteers contracted the disease. Test H0: 0.40 (vaccine ineffective) at = 0.01.

Test size C battery mean life is at least 25 hours.

(1) 1-tailed test of proportion with negative critical value

(2) 2-tailed test of mean with both negative and positive critical values

(3) 1-tailed test of mean with negative critical values

(4) 1-tailed test of paired-data with positive critical value

(5) 2-tailed test of means of 2 independent populations