# Can someone please help me with this standard deviation problem?

### 2 Answers

- PuzzlingLv 73 months ago
A z-score of ±2.17 will result in 97% of the data being within that range (leaving 1.5% on either end).

So just turn those back into raw scores.

x = μ ± zσ

x = 6.9 ± 2.17 * 1

6.9 - 2.17 = 4.73

6.9 + 2.17 = 9.07

Answer:

4.73 ≤ x ≤ 9.07

- 3 months ago
Sorry. Didn't post right. Here is the question.

Engineers must consider the breadths of male heads when designing helmets. The company researchers have determined that the population of potential clientele have head breadths that are normally distributed with a mean of 6.9-in and a standard deviation of 1-in. Due to financial constraints, the helmets will be designed to fit all men except those with head breadths that are in the smallest 1.5% or largest 1.5%.

What is the minimum head breadth that will fit the clientele?

min =

What is the maximum head breadth that will fit the clientele?

min =