To be able to say with 95% confidence that the standard deviation of a data set is within 10% of the population's standard deviation, the number of observations within the data set must be
Greater than or equal to what quantity?
A)805
B)192
C)335
D)250

Question

Quizplus · Accepted Answer

To estimate the population standard deviation with a certain level of confidence and precision, we use the formula for the sample size calculation in estimation problems. Specifically, for estimating a population standard deviation σ with a sample standard deviation s, the sample size n is crucial to achieve a desired confidence level and precision. The formula involving the chi-square distribution is used because the sample variance follows a chi-square distribution. However, without the exact formula or additional context provided in the question, it's challenging to derive the precise number directly. The correct choice, based on statistical principles and typical scenarios involving estimation of standard deviation, is chosen as the closest or most reasonable option given typical statistical tables and calculations for a 95% confidence level and 10% precision.

To Be Able to Say with 95% Confidence That the Standard