I need solve this questions of Statistics 213

QUESTION 1 The standard error of the sample mean decreases as the sample size increases. is never larger than the standard deviation of the population. . All of the options are correct. measures the variability of the mean from sample to sample. QUESTION 2 The waiting time (in minutes) of customers at a fast food outlet is normally distributed. A random sample of 15 customers is selected and the 99% confidence interval for the population mean waiting time is obtained as (1.87,2.33). Find the standard deviation used to construct the 99% confidence interval. Round your answer to three decimal places. QUESTION 3 Which of the following would produce the narrowest confidence interval for u? .93% confidence interval with n = 100. 90% confidence interval with n = 200. .93% confidence interval with n = 200. .90% confidence interval with n = 100. QUESTION 4 Suppose the age of cars on the road is normally distributed with a mean of 9.4 years. If the standard deviation is known to be 2.2 years, what is the probability that 16 randomly selected cars have been on the road between 10 and 11 years? Round your answer to four decimal places. QUESTION 5 The monthly salaries of employees of a construction company is normally distributed and averaged at AED 16,000 with a standard deviation of AED 2500. Find the minimum and the maximum salaries symmetrically distributed around the population mean, that will include 86% of the sample means X , based on samples of 25 employees. Round your answer to the nearest dirham. QUESTION 6 Assume that the time spent by students in extra curricular activities per week is normally distributed with a standard deviation of 12.43 hours. A random sample of 32 students is selected. Find the standard error of the sampling distribution of the sample mean time? Round your answer to two decimal places