Question

The amount of Jen's monthly phone bill is normally distributed with a mean of $70 and a standard deviation of $12. Fill in the blanks. 68% of her phone bills are between $___ and $___.

Answer 1

Explanation:

To find the range within which 68% of Jen's phone bills fall, we can use the properties of the normal distribution.

The normal distribution is symmetrical, so we know that 34% of the phone bills are below the mean and 34% are above the mean.

To find the values that correspond to these percentages, we can use the concept of standard deviations.

Since the standard deviation is $12, we can determine the values by adding and subtracting the standard deviation from the mean.

1. To find the lower value, we subtract one standard deviation from the mean: $70 - $12 = $58.

2. To find the upper value, we add one standard deviation to the mean: $70 + $12 = $82.

Therefore, 68% of Jen's phone bills fall between $58 and $82.