A Recipe Submitted to a Magazine by One of Its $\begin{array} { l l l l l l l l l l } 54 & 55 & 58 & 59 & 59 & 60 & 61 & 61 & 62 & 65 \end{array}$

Essay

A recipe submitted to a magazine by one of its subscribers states that the mean baking time for a cheesecake is 55 minutes. A test kitchen preparing the recipe before it is published in the magazine makes the cheesecake 10 times at different times of the day in different ovens. The following baking times (in minutes) are observed.

$\begin{array} { l l l l l l l l l l } 54 & 55 & 58 & 59 & 59 & 60 & 61 & 61 & 62 & 65 \end{array}$

Assume that the baking times belong to a normal population. Test the null hypothesis that the mean baking time is 55 minutes against the alternative hypothesis $\mu > 55$ . Use $\alpha = .05$ .