The lengths of one-year-old baby girls can be described using a normal distribution with a mean of 29 inches and a standard deviation of 1.2 inches. using the empirical '68-95-99.7' rule, what percent of one-year-old girls are between 26.6 and 31.4 inches?

The '68-95-99.7' rule says

-About 68% of values fall within one standard deviation of the mean.

-About 95% of the values fall within two standard deviations from the mean.

-Almost all of the values — about 99.7% — fall within three standard deviations from the mean.

Here

Hence the values fall within two standard deviations from the mean. The corresponding percentage is 95%.

use an equation of ratios to determine the amount of gas needed to fill the tank.

    0.2             0.8

  =    

288.75             x

                                                              231 gal

so, 0.2x = (0.8)(288.75 gal), and x = = 1155 gal.

                                                                0.2

it would take 1155 gal. to fill the tank.

the cost would be

1155 gal         $3

* = $3465   (answer)

      1           1 gal

hope this you