Answer:
a) 99.7%
b) 68%
Step-by-step explanation:
= Mean = 168 cm
= Standard deviation = 6 cm
a. 150 cm and 186 cm
![168-6* 3=150](https://img.qammunity.org/2020/formulas/social-studies/high-school/1y0u4k639srmxptt3d4bili4u27ijpeaud.png)
![168+6* 3=186](https://img.qammunity.org/2020/formulas/social-studies/high-school/68add1umnr255g2818iypdx0fdrm2l00sg.png)
They vary by 3 standard deviations. So, 99.7% of men are between 150 and 186 cm
b. 162 cm and 174 cm
![168-6* 1=162](https://img.qammunity.org/2020/formulas/social-studies/high-school/3138bqb5uq25f158rj6h4yezgyk8uxp1dz.png)
![168+6* 1=174](https://img.qammunity.org/2020/formulas/social-studies/high-school/kl0qoivnb3dhzby3ir6upesxtio1uv5rbi.png)
They vary by 1 standard deviations. So, 68% of men are between 162 and 174 cm