A researcher wants to estimate the difference in the means of two populations. A random sample...

A researcher wants to estimate the difference in the means of two populations. A random sample of 36 items from the first population results in a sample mean of 430. A random sample of 49 items from the second population results in a sample mean of 460. The population standard deviations are 120 for the first population and 140 for the second population. From this information, a 95% confidence interval for the difference between means of the first population and the second population is _______. Select one: a. -102.83 to 42.43 b. -87.60 to 27.60 c. -76.53 to 16.53 d. -95.90 to 35.90

Solutions

Expert Solution

Given:

n1=36 ,

The 95%confidence interval for the difference of two population meanis given by:

where

Therefore 95% confidence interval becomes

Hence the 95% confidence interval is:

Therefore b) is the correct choice.

milcah answered 2 hours ago

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