Is smoking during pregnancy associated with premature births? Toinvestigate this question, researchers selected a random sample of131 pregnant women who were smokers. The average pregnancy lengthfor this sample of smokers was 262 days. From a large body ofresearch, it is known that length of human pregnancy has a standarddeviation of 16 days. The researchers assume that smoking does notaffect the variability in pregnancy length. Find the 95% confidenceinterval to estimate the length of pregnancy for women who smoke.(Note: The critical z -value to use, z c , is: 1.960) ( , ) Youranswer should be rounded to 3 decimal places.
