Question: Seven sixth grade children were randomly selected to participate in a teaching experiment. At the end of the experiment the children completed a test to assess sixth-grade school achievement which has been standardised to have a mean = 300. The resulting achievement test scores are:

386 311 374 316 303 298 387

Showing all workings, determine whether the data provide sufficient evidence of change in the average test scores of the participants has increased? Test at the 5% level of significance.