Case study chapter 5-7 A statistics professor asked her students whether or not
ID: 3327083 • Letter: C
Question
Case study chapter 5-7 A statistics professor asked her students whether or not they were registered to vote. In a sample of 50 of her students (randomly sampled from her 700 students), 35 said they were registered to vote. 1) Find a 95% confidence interval for the true proportion of the professor's students who were registered to vote. (Make sure to check any necessary conditions and to state a conclusion in the context of the problem.) 2) Explain what 95% confidence means in this context. 3) What is the probability that the true proportion of the professor's students who were registered to vote is in 4) According to a Gallup poll, about 73% of 18-to 29-year-olds said that they were registered to vote. Does the 5) If the professor only knew the information from the Gallup poll and wanted to estimate the percentage of her your confidence interval? 73% figure from Gallup seem, reasonable for the professor's students? Explain. students who were registered to vote to within ±4% with 95% confidence, how many students should she sample?Explanation / Answer
as per chegh policies i am answering Q1 only
1)
CI = p +- z(a/2)*sqrt(p*(1-p)/n)
CI = (0.5729, 0.8270)
2)
i am 95% confident that estimated popn proportion of professor's students who were registered to vote lies in the interval (0.5729, .8270)
n= 50 X= 35 P= X/n 0.7