In a test of the MicroSort method of gender selection, 369 babies are born to couples trying to have baby girls, and 207 of those babies are girls.

If the gender-selection method has no effect and boys and girls are equally likely, find the mean and standard deviation for the numbers of girls born in groups of 369.
(Round answer to one decimal place.)
$\displaystyle \mu=$
(Round answer to two decimal places.)
$\displaystyle \sigma=$

Give the interval of usual values for the number of girls born in groups of 369.
(Enter answer as an interval using square-brackets only with whole numbers.)
usual values =

Does it appear that the gender-selection method appears to be effective?