The SAT scores have an average of 1200 with a standard deviation of 60. A sample of 36 scores is selected.What is the probability that the sample mean will be larger than 1224? Round your answer to three decimal places.

Respuesta :

Answer: 0.008

Step-by-step explanation:

Given: Mean : [tex]\mu=1200[/tex]

Standard deviation : [tex]\sigma = 60[/tex]

Sample size : [tex]n=36[/tex]

The formula to calculate z-score is given by :_

[tex]z=\dfrac{x-\mu}{\dfrac{\sigma}{\sqrt{n}}}[/tex]

For x= 1224, we have

[tex]z=\dfrac{1224-1200}{\dfrac{60}{\sqrt{36}}}=2.4[/tex]

The P-value = [tex]P(z>2.4)=1-P(z<2.4)=1-0.9918024=0.0081976\approx0.008[/tex]

Hence, the probability that the sample mean will be larger than 1224 =0.008