Answer:
a) 99.7%
b) 68%
Explanation:
[tex]\mu[/tex] = Mean = 168 cm
[tex]\sigma[/tex] = Standard deviation = 6 cm
a. 150 cm and 186 cm
[tex]168-6\times 3=150[/tex]
[tex]168+6\times 3=186[/tex]
They vary by 3 standard deviations. So, 99.7% of men are between 150 and 186 cm
b. 162 cm and 174 cm
[tex]168-6\times 1=162[/tex]
[tex]168+6\times 1=174[/tex]
They vary by 1 standard deviations. So, 68% of men are between 162 and 174 cm