10 . The Body Mass Index ( BMI ) of a group of tennis players is studied . Ten players are randomly selected and their BMIs are measured . It is given that the 95 % confidence interval for the population mean is ( 18.95 , 25.15 ) .
( a ) Find an unbiased estimate of the population mean .
Let
2
� be the known population variance .
( b ) Find � .
[ 2 ]
[ 3 ]
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