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Determine the point estimate. An article in an educational journal discussing a non-conventional high school reading program reports a 95% confidence interval of (520 , 560) for the average score on the reading portion of the SAT. The study was based on a random sample of 20 students and it was assumed that SAT scores would be approximately normally distributed. Determine the sample mean that was used to build this confidence interval.

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Answer:

Step-by-step explanation:

CI ( 95 % )   means   α = 5 %    α  = 0,05   α /2 = 0,025

If we have a normal distribution and build a CI by symmetry such CI has as a middle point the mean in this case

CI 95 %  =  ( 520 ;  560 )

the mean is (520 + 560 ) / 2  

mean  = 540