Question

# 1. In a random sample of 58 people aged 20-24, 22.7% were smokers. In a random...

1. In a random sample of 58 people aged 20-24, 22.7% were smokers. In a random sample of 110 people aged 25-29, 29.5% were smokers. Calculate the margin of error for a 95% confidence interval that can be used to estimate the difference between the population proportions p1 − p2 of the smokers in these age groups.

2. Confidence interval for the difference between population proportions.
(Assume that the samples are randomly selected and independent.)

Sample statistics: x 1 = 36, n 1 = 64 and x 2 = 47, n 2 = 71;
Construct a 95% confidence interval for the difference between population proportions p1 – p2

Select one:

a. 0.368 < p1 – p2 < 0.757

b. -0.263 < p1 – p2  < 0.064

c. -0.294 < p1 – p2 < 0.757

d. 0.399 < p1 – p2  < 0.726

3. As a result of running a simple regression on a data set, the following estimated regression equation was obtained:

= 9.7 + 13.4x

Furthermore, it is known that SST = 622, and SSE = 150.

Calculate the correlation coefficient R; round your answer to three decimal places

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