If we have data that have been sampled from a population that is normally distributed with a mean of 50 and a standard deviation of 10, we would expect that 95% of our observations would lie in the interval that is approximately
A) 30-70.
B) 35-50.
C) 45-55.
D) 70-90.

Question

Quizplus · Accepted Answer

The 95% confidence interval for a normally distributed dataset is calculated as the mean plus or minus 1.96 times the standard deviation. In this case, with a mean of 50 and a standard deviation of 10, the interval is 50 ± (1.96*10), which roughly equals 30 to 70.

If We Have Data That Have Been Sampled from a Population