o find the value of t-critical, we first must know the degrees of freedom for the t-distribution we need to use in this case. We must use  degrees of freedom in this situation. Once we are clear about the degrees of freedom, we can compute the value of t-critical, the critical value for the t-distribution. t-critical =         (to three places after the decimal)

QUESTION 1 Find the confidence level related to the critical value z 88% 12% 93% 94% Za/2=1.555 QUESTION 2 A research study reported a 95% confidence interval for the mean time of hip surgeries based on a sample of 91 patients as (116 minutes, 138 minutes). Which of the following statements is correct about the given interval? A. Incorrect B. Correct ✓ The mean time of hip surgeries of the 91 patients in the selected sample falls between 116 and 138 minutes. ✓ The mean time of hip surgeries of any sample of 91 patients will fall between 116 and 138 minutes. 95% of hip surgeries take between 116 and 138 minutes. We are 95% confident that the mean time of hip surgeries will be between 116 and 138 minutes. QUESTION 3 A survey of 64 popular restaurants is used to estimate the mean number of kitchen employees. Assume that the number of kitchen employees is right-skewed, which distribution should be used to construct the confidence interval? Neither standard normal distribution nor t…