Question 1171771: Dr. Noritz wants to find confidence intervals for the true population proportion of Buffalo State graduates that earn an MBA after graduation. Dr. Noritz samples 400 students and discovers that 40 eventually earn an MBA.
a. Test to see if you can use the normal distribution.
b. Find the 95% confidence interval for the true proportion of graduates that earn an MBA. Make
sure you draw the graph in order to receive credit.
c. Find the 90% confidence interval for the true proportion of graduates that earn an MBA Make sure
you draw the graph in order to receive credit.
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! np and n(1-p)>10 so can
95% CI half-interval is z*sqrt(p*(1-p)/n)=1.96*sqrt(0.1*0.9/400)=0.0294
the 95%CI is (0.0706, 0.1294)
the 90th CI uses 1.645 for z and the SE is 0.0247 so the interval is (0.0753, 0.1247)
Draw the normal distribution emphasizing -2,-1.96,-1.645, -1, 0, 1,1.645, 1.96, and 2.
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