The cholesterol levels of a random sample of 100 men are measured. The sample mean is 188 and the sample standard deviation is 40. Which of the following provides a 95% confidence interval for the population mean?
A) 188$\pm$(1.98)(0.4)
B) 188 $\pm$(1.98)(4)
C) 188 $\pm$ (1.98)(40)
D) 188 $\pm$(1.98)(4000)

Question

Quizplus · Accepted Answer

The 95% confidence interval for the population mean is calculated using the formula: sample mean $\pm$ (z-score)(standard error). The standard error is the sample standard deviation divided by the square root of the sample size, which is 40/√100 = 4. Thus, the correct interval is 188 $\pm$ (1.98)(4).

The Cholesterol Levels of a Random Sample of 100 Men ±\pm±

The Cholesterol Levels of a Random Sample of 100 Men $\pm$