Question

A researcher wishes to estimate the average blood alcohol concentration (BAC) for drivers involved in fatal accidents who are found to have positive BAC values. He randomly selects records from 51 such drivers in 2009 and determines the sample mean BAC to be 0.15 g/dL with a standard deviation of 0.060 g/dL.

a) A histogram of blood alcohol concentration in fatal accidents show that the BAC's are highly skewed right. Expain why yhe large samples

Answer 1

Solution:

We need a large sample , because it states that the histogram is skewed , this means the data does not follow normal distribution. Thus for it to follow normal distribution, we need to have a sample equal to or larger than sample size 30, so that the central limit theorem can be applied and the sample follows normal distribution.