Question

Probability and Statistics

Could you please solve the following questions with specifying the answers

A. A random sample of 1,600 adults in a certain country shows that 72% have smart phones. What is a 80% confidence interval for the percentage of adults having smart phones in this country?

1. 72%±1.85%     b. 72%±1.44%     c.72%±2.24%     d.72%±1.11%

B. If 48% of the 400 voters sampled voted for candidate A over candidate B, what is a 95% confidence for p hat, the estimate for the percentage candidate p that A would receive?

1. 48%±2.5%      b. 48%±5%     48%±10%     d. 48%±1%

C. Twenty-five randomly selected students are asked how many times a month they eat pizza. The average for this sample is x̅₂₅= 11.75 times,but the population mean of all college students is claimed to be μ = 10.60 times. If the null hypothesis is H₀ is μ = 10.60 times and the standard deviation σ = 5 times, should the null hypothesis be rejected at the 5% level of significance? (No table needed)

1. Yes       b.   No      c. Not enough information       

Answer 1