SOLUTION: Supposed the data are SAT scores and follow a normal distribution with a mean of 500 and a standard deviation 100.
a.What percent of the population obtains scores of 410 or less
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-> SOLUTION: Supposed the data are SAT scores and follow a normal distribution with a mean of 500 and a standard deviation 100.
a.What percent of the population obtains scores of 410 or less
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Question 1186323: Supposed the data are SAT scores and follow a normal distribution with a mean of 500 and a standard deviation 100.
a.What percent of the population obtains scores of 410 or less?
b.What is the minimum score needed to rank in the top 5% of the populations?
c.A psychologist wishes to test a new learning strategy on the bottom 15% of those who took the Math SAT. What cut-off score should she use to select participants for her study?
You can put this solution on YOUR website! z=(x-mean)/sd
a.z=(410-500)/100 or -0.9
probability of z < -0.9 is 0.1841
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b. top 5% has a z-value of 1.645
so 1.645=(x-500)/100
164.5=x-500
x=664.5
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bottom 15% is using 2ndVARS3 invnormcdf(0.15,0,1) ENTER or -1.04
so -104=x-500
x=396 for the score.
Find out how much the instructor wants the z rounded, since it changes the answer slightly.
