The mean height of women in a country​ (ages 20minus​29) is 64.2 inches. A random sample of 50 women in this age group is selected. What is the probability that the mean height for the sample is greater than 65​ inches? Assume sigmaequals2.58. Round to four decimal places.

Respuesta :

Answer: 0.0142

Step-by-step explanation:

Given : The mean height of women in a country​ (ages 20 - ​29) is 64.2 inches.

i.e. [tex]\mu=64.2[/tex]

Also, [tex]\sigma=2.58[/tex]

Sample size : n= 50

Let x denotes the height of women.

Then, the probability that the mean height for the sample is greater than 65​ inches :-

[tex]P(x>65)=1-P(x\leq 65)\\\\=1-P(\dfrac{x-\mu}{\dfrac{\sigma}{\sqrt{n}}}\leq\dfrac{65-64.2}{\dfrac{2.58}{\sqrt{50}}})\\\\=1-P(z\leq2.193)\ \ [\because z=\dfrac{x-\mu}{\dfrac{\sigma}{\sqrt{n}}}]\\\\=1-0.9858463\ \ [\text{By using z-value table or calculator}]\\\\=0.0141537\approx0.0142[/tex]

Hence, the the probability that the mean height for the sample is greater than 65​ inches = 0.0142