Question
In: Statistics and Probability
1. A researcher wishes to estimate the proportion of left-handers among a certain population. In a...
1. A researcher wishes to estimate the proportion of left-handers among a certain population. In a random sample of 900 people from the population, 74% are left-handed.
a. Find the margin of error for the 95% confidence interval for the population proportion of the left-handers.
b. Find the 95% confidence interval for the population proportion of the left-handers to four decimal places.
Solutions
Expert Solution
Solution:
Given:
Sample size = n= 900
Sample proportion of left-handed = 
Part a) Find the margin of error for the 95% confidence interval for the population proportion of the left-handers.
We need to find zc value for c=95% confidence level.
Find Area = ( 1 + c ) / 2 = ( 1 + 0.95) /2 = 1.95 / 2 = 0.9750
Look in z table for Area = 0.9750 or its closest area and find z value.
Area = 0.9750 corresponds to 1.9 and 0.06 , thus z critical value = 1.96
That is : Zc = 1.96
thus
Part b. Find the 95% confidence interval for the population proportion of the left-handers
orchestra answered 2 years agoRelated Solutions
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