Respuesta :
Answer:
The required probability is 0.6517
Step-by-step explanation:
Consider the provided information.
North Catalina State University's students can be approximated by a normal model with mean 130 and standard deviation 8 points.
μ₁ = 130 and σ₁ = 8
Chapel Mountain University's students can be approximated by a normal model with mean 120 and standard deviation 10 points.
μ₂ = 120 and σ₂ = 10
As both schools have IQ scores which is normally distributed, distribution of this difference will also be normal with a mean of μ₁-μ₂ and standard deviation will be [tex]\sqrt{\sigma_1^2+\sigma_2^2}[/tex]
Therefore,
μ = 130-120=10
[tex]\sigma = \sqrt{8^2+10^2}=12.806[/tex]
Now determine the probability of North Catalina State University student's IQ is at least 5 points higher than the Chapel Mountain University student's IQ:
[tex]z=\frac{\bar x-\mu}{\sigma}[/tex]
[tex]z=\frac{5-10}{12.806}\approx-0.39[/tex]
Now by using the z table we find the z- score of -0.39 is 0.6517.
Hence, the required probability is 0.6517