Q7 Part 2

#1 Find the critical value t_c for the confidence level c=0.90 and sample size n=15.

#2 Construct the indicated confidence interval for the population mean using the t-distribution. Assume the population is normally distributed.

c=0.99, x=14.7, s=2.0, n=5

#3 Let p be the population proportion for the following condition. Find the point estimates for p and q.Of 864 children surveyed, 115 plan to join the armed forces in the future.

(a) The point estimate for p, p, is

(b) The point estimate for q, q, is

(Round to three decimal places as needed.)

#4 A researcher wishes to estimate, with 99% confidence, the population proportion of adults who think Congress is doing a good or excellent job. Her estimate must be accurate within 5%

of the true proportion.

(a) No preliminary estimate is available. Find the minimum sample size needed.

(b) Find the minimum sample size needed, using a prior study that found that 20% of the respondents said they think Congress is doing a good or excellent job.(

c) Compare the results from parts (a) and (b).

#5 Find the critical values 2L and 2R for the given confidence level c and sample size n.

c=0.99,

n=26