Help with business statistic hw!?

Question

a newsletter publisher believes that over 37 percent of their readership own a rolls royce. a random sample of 250 found that 42 percent of the readers owned a rolls royce. is there sufficient evidence at the 0.10 level to subtiantiate the publisher's claim?

i found z but how do i find the decision rule z=1.64

reject H0 if z > ??

Answer 1

Confidence Interval for a Population Proportion μ

1.Null hypothesis: H0 μ = 0.37

2.Alternative hypothesis: Ha μ < 0.37

Test and Confidence Interval for One Proportion

Test of p = 0.5 vs p not = 0.5

                                                                             Exact

Sample    X    N  Sample p         90% CI         P-Value

1       105  250  0.420000  (0.367573, 0.473854)    0.013

That is, with a confidence level of 90%, the proportion of readership is in the interval of 36.7% to 47.4%