The Manager of a Fast Food Restaurant Is Investigating the Average

The manager of a fast food restaurant is investigating the average number of fries per Large-sized offered to customers, to assess quality control. The manager took a random sample of five Large-sized orders of fries, and counted the number of fries per serve, with the results given below: $\begin{array}{|r|r|r|r|r|}\hline73 & 75 & 83 & 68 & 78 \\\hline\end{array}$ Assume that the number of French fries served at this fast food restaurant is normally distributed. Can we infer at the 5% significance level that the average number of fries served in a Large-sized order of fries at this fast food restaurant is over 70?