Suppose a local pizzeria delivers pizzas every day of the week and their delivery times are normally distributed with a mean of 30 minutes with a standard deviation of 4 minutes. Determine the interval that contains the middle 80% of delivery times.

interval in minutes = (24.88, 35.12)

Step-by-step explanation:

we can use the following formula:

interval = population mean ± (z · σ)

interval = 30 minutes ± (1.28 · 4 minutes)

interval in minutes = (30 - 5.12), (30 + 5.12) = (24.88, 35.12)

the answer is:

the correct option:

b.

to solve the problem, we need to remember how to operate to simplify exponential expressions using the logarithms.

we are given the equation:

then, using placing logarith with base 7 on both sides of the equation, we have:

so, rounding the obtained result to two decimal places (nearest hundreth), we have:

hence, we have that the correct option:

b.

have a nice day!

step-by-step explanation: