The amount of a monthly phone bill is normally distributed with a mean of $60 and a standard deviation of $12. Fill in the blanks:
68% of her phone bills are between $______________ and $______________.
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To fill in the blanks, we need to find the range of values that corresponds to 68% of the phone bills. We know that the phone bills are normally distributed with a mean of $60 and a standard deviation of $12.
First, let's find one standard deviation above and below the mean. Since the standard deviation is $12, one standard deviation below the mean would be $60 - $12 = $48, and one standard deviation above the mean would be $60 + $12 = $72.
Next, we know that in a normal distribution, approximately 68% of the values fall within one standard deviation of the mean. So, 68% of the phone bills would fall between $48 and $72.
Therefore, we can fill in the blanks as follows:
68% of her phone bills are between $48 and $72.