Suppose that the time required to complete a 1040R tax form is normally distributed with a mean of 100 minutes and a standard deviation of 10 minutes. W proportion of 1040R tax forms will be completed in more than 85 minutes? Round your answer to at least four decimal places.

In​ 2007, the mean rate of violent crime​ (per 100,000​ people) for 10 regions in the northeast of a certain country was 334. The standard deviation was 126. Assume that the distribution of violent crime rates is unimodal and symmetric. sing the Empirical​ Rule, between what two values would you expect to find about​ 68% of the​ rates?   Approximately​ 68% of the observations fall within the interval

Suppose that the time required to complete a 1040R tax form is normally distributed with a mean of 110 minutes and a standard deviation of 15 minutes. What proportion of 1040R tax forms will be completed in 0 less than 85 minutes? Round your answer to at least four decimal places,

How to find the standard deviation after we have found the range?

Suppose the scores on your last Algebra 2 test were normally distributed, with a mean of 81% and a standard deviation of 3%. To show you how you compared to your classmates, the teacher did not record your grades as per- centages, instead, she wrote them as z-scores. You look at your paper and see "2.66" written at the top. What was your score as a percentage? Explain how you determined your answer.

IQ scores are normally distributed with a mean of 100 and a standard deviation of 15.  What is the minimum IQ required to be able to correctly claim to be in the "top 5%" of IQ scores. Round to the nearest whole number.

About what percent of x values lie between the second and third standard deviation (both sides)?

Suppose that we doubled everyone's original salary what will happen to the mean and sd