SOLUTION: Results from previous studies showed 79% of all high school seniors from a certain city plan to attend college after graduation. A random sample of 200 high school seniors from thi

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Question 938371: Results from previous studies showed 79% of all high school seniors from a certain city plan to attend college after graduation. A random sample of 200 high school seniors from this city reveals that 162 plan to attend college. Does this indicate that the percentage has increased from that of previous studies? Test at the 5% level of significance.
What is your conclusion?

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
Ho: p =.79 (claim)
Ha: p > .79
....
Sample: p = 162/200 = .81
....
test stat z+=blue+%28x+-+mu%29%2Fsqrt%28blue%28p%281-p%29%2Fn%29%29 : z = .02/sqrt[0.79*0.21/200) = .6944
P(z > .6944) = normalcdf(.6944,100)
........
Test at the 5% level of significance
normalcdf(.6944,100) > .05
.......
Test results support the claim that p = .79
......
For the normal distribution: Below: z = 0, z = ± 1, z= ±2 , z= ±3 are plotted.
Note: z = 0 (x value: the mean) 50% of the area under the curve is to the left and 50% to the right