Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability (.05 each direction) and its Z score = 1.645.
90% = mean ± 1.645 SEm
SEm = SD/√n
A filing machine designed to fill soda bottles with 16 ouncesof soda. The distribution for the weight of the bottles is normal. Twenty bottles are selected and weighted. The sample mean is 15.3 ounces and the standard deviation is 1.5 ounces . Develop a 90% confidence interval for this sample.
1 answer
1 answer