College

How many pounds a statistician can bench press is normally distributed with a mean of 139 and a standard deviation of 46. If Scott can bench 145 pounds, approximately what percentage of statisticians can bench more than Scott?

Answer :

Answer:

The percentage is [tex]P(X > 145 ) = 44.811\%[/tex]

Step-by-step explanation:

From the question we are told that

The mean is [tex]\mu = 139[/tex]

The standard deviation is [tex]\sigma = 46[/tex]

The weight Scott can bench is x = 145 pounds

Generally the percentage of statisticians that can bench more than Scott is mathematically represented as

[tex]P(X > x ) = P(\frac{X - \mu }{\sigma } > \frac{x- 139 }{46 } )[/tex]

=> [tex]P(X > 145 ) = P(\frac{X - \mu }{\sigma } > \frac{145 - 139 }{46 } )[/tex]

[tex]\frac{X -\mu}{\sigma } = Z (The \ standardized \ value\ of \ X )[/tex]

[tex]P(X > 145 ) = P(Z > 0.13043)[/tex]

From the z table

The area under the normal curve to the right corresponding to 0.13043 is

[tex]P(Z > 0.13043) = 0.44811[/tex]

=> [tex]P(X > 145 ) = 0.44811[/tex]

Converting to percentage

[tex]P(X > 145 ) = 0.44811 * 100[/tex]

=> [tex]P(X > 145 ) = 44.811\%[/tex]