Contradicting H1 An important step in conducting the sign test is to determine whether the sample data contradict the alternative hypothesis H1. For the sign test described in Exercise 1, identify the null hypothesis and the alternative hypothesis, and explain how the sample data contradict or do not contradict the alternative hypothesis.

Two samples are given showing the weights of students (kgs) in September and April.

The sign test is a type of non-parametric test that can be used to test the claim of no difference in the values of the weights between September and April.

The null hypothesis is defined as follows.

There is nodifference in the weights between the two months.

The alternative hypothesis is defined as follows.

There is a difference in the weights between the two months.

The signs of the differences between the September weights and April weights are shown below.

The number of positive signs is equal to 2.

The number of negative signs is equal to 7.

There appears to be a difference between the two signs.

There appears to be a difference in the weights of the two months. As there are 2 positive and 7 negative signs, it can be said that the sample data does not contradict the alternative hypothesis.