Question

PROBLEM 3:

Is there a difference between the two suppliers of solar panels in proportion of defectives?

Test at significance level =.01

Suppler A: 30/600 solar panels =defective

Suppler B: 10/400 solar panels =defective

PROBLEM 4:

Which school does better on the CPA exam? Test at .10 significance level.

CUNY: 30/100 Passed CPA Exam (all four parts)

SUNY: 40/180 Passed CPA Exam (all four parts)

PROBLEM 5:

Effect of estrogen on Alzheimer’s Disease.

Test at α=.05

Of the Women receiving estrogen: 7/100 developed Alzheimer’s

Of the Women not receiving estrogen: 27/150 developed Alzheimer’s

PROBLEM 6:

Direct Mail –Should Company use Sweepstakes, or not? Test at α=.05

Sweepstakes No Sweepstakes

Mailed Out 5,000 4,000

#of Orders 100 60

Answer 1

Ans 3 ) using minitab>stat>basic stat>two sample z

we have

Test and CI for Two Proportions

Sample X N Sample p
1 30 600 0.050000
2 10 400 0.025000

Difference = p (1) - p (2)
Estimate for difference: 0.025
99% CI for difference: (-0.00548896, 0.0554890)
Test for difference = 0 (vs ≠ 0): Z = 1.98 P-Value = 0.048

since p value is greater than 0.01 so we conclude that there is no difference between two suppliers.

Ans 4) using minitab>stat>basic stat>2 proportion

we have

Test and CI for Two Proportions

Sample X N Sample p
1 30 100 0.300000
2 40 180 0.222222

Difference = p (1) - p (2)
Estimate for difference: 0.0777778
90% CI for difference: (-0.0132143, 0.168770)
Test for difference = 0 (vs ≠ 0): Z = 1.44 P-Value = 0.150

since 90% confidence interval contain 0 so we conclude that both school do same.

Ans 5) using minitab>stat>bsic stat>two sample proportion

we have

Test and CI for Two Proportions

Sample X N Sample p
1 7 100 0.070000
2 27 150 0.180000

Difference = p (1) - p (2)
Estimate for difference: -0.11
95% CI for difference: (-0.189251, -0.0307486)
Test for difference = 0 (vs ≠ 0): Z = -2.49 P-Value = 0.013

since p value is 0.013 < 0.05

so there is an Effect of estrogen on Alzheimer’s Disease.

Ans 6 ) using minitab>stat>basic stat>two sample proportion

we have

Test and CI for Two Proportions

Sample X N Sample p
1 100 5000 0.020000
2 60 4000 0.015000

Difference = p (1) - p (2)
Estimate for difference: 0.005
95% CI for difference: (-0.000408133, 0.0104081)
Test for difference = 0 (vs ≠ 0): Z = 1.78 P-Value = 0.074

since p value is greater than 0.05 so Company should not use Sweepstakes.