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

Respuesta :

Answer:

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

Step-by-step explanation:

From the question we are told that

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

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

Β  Β The weight Scott can bench is Β x = Β 145 pounds

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

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

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

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

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

From the z table Β 

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

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

=> Β [tex]P(X > 145 ) = 0.44811[/tex]

Converting to percentage

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

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

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