SOLUTION: Use the empirical rule to solve the following problems below Assume all the data follow the normal distribution: A researcher is studying the proportion of adults who support a par

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Question 1206720: Use the empirical rule to solve the following problems below Assume all the data follow the normal distribution: A researcher is studying the proportion of adults who support a particular policy. A random sample of 200 adults was selected, and 150 of them indicated support for the policy. a. Find a 95% confidence interval for the true proportion of adults who support the policy.
Answer by MathLover1(20850) About Me  (Show Source):
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if a random sample of 200 adults was selected, and 150+of them indicated support for the policy, we have
p=150%2F200=3%2F4=0.75
a 95% confidence=> z=1.96
then, confidence interval for the true proportion of adults who support the policy is
p%2B-z%2Asqrt%28p%281-p%29%2Fn%29
0.75%2B-1.96%2Asqrt%280.75%281-0.75%29%2F200%29
0.75%2B-0.06001249869818786
0.75%2B-0.06
0.75-0.06=0.69
0.75%2B0.06=0.81

we are 95% confident there will be between 69% and 81% adults, with a margin of error of 0.06, who support the policy