Question

Problem #2: A weight-loss intervention is assigned to a group of 5 adults. Each adult is weighed before the intervention and after the intervention. The researcher wants to know if the intervention was successful. Use the data, significance chart, and hint section below to answer questions Questions a & b.

Participant	Before weight	After weight
Walter	180	168
Tom	175	164
Connie	140	130
Brock	200	179
Jennifer	150	152

a) Calculate the t-statistic: t = ______

b) Interpret the results:

• The threshold to compare the statistic at = 0.05 is _______.

• Is the difference between the groups significant or non-significant?

• Therefore, we (circle one: reject / fail to reject) the null hypothesis, and conclude that

• On average, the participants’ weight (choose one)

  • Significantly decreased after the intervention.

  • significantly increased after the intervention.

  • did not significantly decrease after the intervention.

  • did not significantly increase after the intervention.

Answer 1

The statistical software output for this problem is:

Hence,

a) t statistic = 2.835

b) The threshold to compare the statistic at = 0.05 is 2.132

Is the difference between the groups significant or non-significant? Significant

Therefore, we reject the null hypothesis, and conclude that on average, the participants’ weight Significantly decreased after the intervention.