95 percent of the observations under the normal curve fall within ________ times the sample error.
A)±1.64
B)±1.96
C)±2.58
D)±95
E)±1.95

Question

Quizplus · Accepted Answer

The 95% confidence level corresponds to a z-score of ±1.96. Since the sample error is equal to the standard error of the mean divided by the square root of the sample size, we cannot determine its exact value without additional information. However, we know that approximately 95% of the observations fall within ±2 standard errors of the mean, which is equivalent to ±1.96 times the sample error. Therefore, choice B is the best answer.

95 Percent of the Observations Under the Normal Curve Fall