A woman is told her weight has a standard score (z-score) of -1.5. This means that:_______a. Her weight is 1.5 pounds above average.b. Her weight is 1.5 standard deviations below average.c. Her weight is 1.5 pounds below average.d. Her weight is 1.5 standard deviations above average.

Respuesta :

Answer: b. Her weight is 1.5 standard deviations below average.

Step-by-step explanation:

Given : A woman is told her weight has a standard score (z-score) of -1.5.

Let x denotes a random variable that represents the weight of woman.

Since , [tex]z=\dfrac{x-\mu}{\sigma}[/tex]

, where [tex]\mu[/tex] = Population mean and [tex]\sigma[/tex] = Population standard deviation.

Put z= -1.5 in this , we get

[tex]-1.5=\dfrac{x-\mu}{\sigma}[/tex]

i.e. [tex]-1.5\sigma=x-\mu[/tex]

i.e. [tex]x=\mu-1.5\sigma[/tex]

It means , x is 1.5 standard deviations below the mean value.

This means that: Her weight is 1.5 standard deviations below average.

Hence, the correct answer is b. Her weight is 1.5 standard deviations below average.