Question

If a cup of ice cream is selected. what is the probability that the cholesterol content will be more than 670mg?

Answer 1

Given $\mu=660\ mg, \sigma=35\ mg, n=10$

$$P(X>670)=1-P(X\leq670)$$ $$=1-P(Z\leq\dfrac{670-660}{35/\sqrt{10}})$$ $$\approx1-P(Z\leq0.9035)\approx0.1831$$

The probability that the mean of the sample will be larger than 670 mg is 0.1831.