40% means 40 parts out of 100. If we have made the numerator of the fraction 2, we have divided 40 by 20. To make this fraction equal to 40/100, we have to divide 100 by 20 as well, giving us 5.

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What is the probability that a randomly selected male will have a foot length between 8 and 12.5 inches? P(8 < r < 12.5)=

melisa1 [442]

Answer:

0.8185 or 81.85%

Step-by-step explanation:

The mean length (μ) of an adult foot is 11 and the standard deviation (σ) is 1.5.

The z score is a measure in statistic used to determine the amount of standard deviation by which the raw score (x) is above or below the mean. If the raw score is above the mean, the z score is positive and if the raw score is below the mean the z sore is negative. It is given by:

$z=\frac{x-\mu}{\sigma}$

To calculate the probability that a randomly selected male will have a foot length between 8 and 12.5 inches, we first calculate the z score for 8 inches and then for 12.5 inches.

For 8 inches:

$z=\frac{x-\mu}{\sigma}=\frac{8-11}{1.5}=-2$

For 12.5 inches:

$z=\frac{x-\mu}{\sigma}=\frac{12.5-11}{1.5}=1$

From the normal distribution table, The probability that a randomly selected male will have a foot length between 8 and 12.5 inches = P(8 < x < 12.5) = P(-2 < z < 1) = P(z < 1) - P(z < -2) = 0.8413 - 0.0228 = 0.8185 = 81.85%

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3 years ago