Find the proportion of heights that are within 1 standard deviation of the sample mean and also the proportion that are within 2 standard deviations of the sample mean. use the unrounded values for the mean and standard deviation when doing this calculation. give your answers as decimals to 2 decimal places.

68% of heights that are within 1 standard deviation of the sample mean and 95% are within 2 standard deviations of the sample mean.

Empirical rule states that for a normal distribution, 68% of the values are within one standard deviation from the mean, 95% of the values are within two standard deviation from the mean, 99.7% of the values are within three standard deviation from the mean

Using empirical rule:

68% of heights that are within 1 standard deviation of the sample mean and 95% are within 2 standard deviations of the sample mean.

Find out more on Empirical rule at: link

step-by-step explanation:

given perimeter: 28cm

length: 9cm

atp,

2(l+w)=p of the reactangle

2(9+x)=28

18+2x=28

2x=28-18

x=10/2

x=5

therefore width is 5 cm