Question

i need help on only these please help

10) The monthly earnings of a group of business students are are normally distributed with a standard deviation of 589 dollars. A researcher wants to estimate the mean monthly earnings of all business students. Find the sample size needed to have a confidence level of 95% and a margin of error of 132 dollars. B) 2 C) 77 D) 67 A) 4 Solve the problem. 11) A confidence interval for a population mean, u, has length 12. Find the margin of error. B) 36 C) 12 D) 6 A) 3 Provide an appropriate response. 12) Give an expression for the confidence level in terms of a A) 100a% B) 100(1-a)% C) 1-a% D) 1 - 100% Find the specified t-value. 13) For a t-curve with df - 18, find the t-value having area 0.05 to its right. A) 1.734 B) 1.740 C) 2.101 D) 2.878

Answer 1

10) The margin of error for confidence is
ME = Z1-a/27
.

We need

ME = 132 Z1-a/2 = 132 4589 1.96-02 = 132 n = 76,488276 vn

So the required sample size is 77. Correct answer is (C).

11) The length of   confidence is
221-a/2 = 2ME

Here

.

2ME = 12 ME = 6

Correct answer is (D).

12)In terms of the significance level $\alpha$ , the confidence level is .

Correct answer is (B).

13) We need

Correct choice is (A).