24) Let be a specific value of t. Find such that the following statement is true: P(t ≥ ) = .05 where df = 20.

25) Determine the confidence level for the given confidence interval for μ.
± 1.88 25)

A) 94% B) 3% C) 97% D) 98.5%

26) A random sample of n measurements was selected from a population with unknown mean μ and known standard deviation σ. Calculate a 95% confidence interval for μ for the given situation. Round to the nearest hundredth when necessary.
n = 100, = 74, σ = 2526)

A) 74 ± 0.49B) 74 ± 49C) 74 ± 4.9D) 74 ± 4.11

27) A 90% confidence interval for the average salary of all CEOs in the electronics industry was constructed using the results of a random survey of 45 CEOs. The interval was Give a practical interpretation of the interval.27)

A) We are 90% confident that the mean salary of the sampled CEOs falls in the interval $110,389 to $128,192.
B) We are 90% confident that the mean salary of all CEOs in the electronics industry falls in the interval $110,389 to $128,192.
C) 90% of all CEOs in the electronics industry have salaries that fall between $110,389 to $128,192.
D) 90% of the sampled CEOs have salaries that fell in the interval $110,389 to $128,192.

28) A random sample of 250 students at a university finds that these students take a mean of 15.3 credit hours per quarter with a standard deviation of 1.6 credit hours. Estimate the mean credit hours taken by a student each quarter using a 95% confidence interval. Round to the nearest thousandth.28)

A) 15.3 ± .157B) 15.3 ± .198C) 15.3 ± .013D) 15.3 ± .010