Question

The Acme Company manufactures widgets. The distribution of widget weights is bell-shaped. The widget weights have a mean of 64 ounces and a standard deviation of 5 ounces.

Use the Standard Deviation Rule, also known as the Empirical Rule.

Suggestion: sketch the distribution in order to answer these questions.

a) 95% of the widget weights lie between  and

b) What percentage of the widget weights lie between 59 and 74 ounces?  %

c) What percentage of the widget weights lie above 49 ?

Answer 1

Use the Standard Deviation Rule, also known as the Empirical Rule (68-95-99.7 rule).

Percentage between 59 and 74 ounces is 34%+34%+13.5% = 81.5%

Percentage above 49 is 2.35%+13.5%+34%+34%+13.5%+2.35%+0.15% = 99.85%