Problem
Listed in the accompanying table are numbers of hospital admissions in one region due to traffic accidents on different Fridays falling on the 6 th day of a month and the following 13 th day of the month. Assume that we want to use a 0.01 significance level to test the claim that the data support the claim that fewer hospital admissions due to traffic accidents occur on Friday the 6 th than on the following Friday the 13th. Identify the null hypothesis and alternative hypothesis. Friday 6th Friday 13 th 10 4 12 9 2 5 12 12 11 13 16 12 4 $\vdots$ Let the differences be the accidents on the 6 th minus the accidents on the 13 th. The null hypothesis is $\mathrm{H}_{0}: \mu_{d}=0$. (Type an integer or a decimal. Do not round.) The alternative hypothesis is $\mathrm{H}_{1}: \mu_{\mathrm{d}} \quad \mathbf{\nabla} \square$. (Type an integer or a decimal. Do not round.)
Solution
Step 1 ：The null hypothesis is \(H_{0}: \mu_{d}=0\). This means that there is no difference in the number of hospital admissions due to traffic accidents between Friday the 6th and the following Friday the 13th.
Step 2 ：The alternative hypothesis is \(H_{1}: \mu_{d}<0\). This means that there are fewer hospital admissions due to traffic accidents on Friday the 6th than on the following Friday the 13th.
