If amount of utility bill is normally distributed with a mean of $105 and a standard deviation of $20. What percentage of your bills would you expect to be between $85 and $125?

68% of your bills between $85 and $125

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean = $105

Standard deviation = $20

What percentage of your bills would you expect to be between $85 and $125?

85 = 105 - 20

125 = 105 + 20

Within one standard deviation of the mean, so by the Empirical Rule, 68% of your bills between $85 and $125

54 km / hours

step-by-step explanation:

we need to convert seconds to hours

60 seconds = 1 minutes

60 minutes = 1hour

15 m         60 second   60 minutes

  * *         = 54000 meters/ hour

second     1 minute             1 hour

now we need to convert meters to km

1000 m = 1 km

54000 m       1 km

*   = 54 km / hours

hour               1000m