Question

A study was designed to investigate the idea that death rate in the United States is influenced by
changes in taxes. Researchers determined death rates in the United States during the 14 days
before, and the 14 days after, an increase in estate tax for various time periods.

What test would you use to determine if death rate changed significantly after the
estate tax rate change?
Is this two tailed or one tailed paired t-test? What would be the alternate hypothesis?

Year 1917 1917 1919 1924 | 1926 1932 1934 1935 1940 1941 1942 Death rate 14 days after 22.21 18.86 28.21 31.64 19.43 9.50 24.29 26.64 35.07 38.86 28.50 Death rate 14 days before 24.93 20.00 29.93 30.64 20.86 10.14 28.00 25.29 35.00 37.57 34.79

Answer 1

here we wants to test if death rate changed significantly after the estate tax rate exchange

So this is two tailed paired t - test because  death rate changed significantly after the
estate tax rate change.

Null hypothesis Ho : $\mu$ D = 0

alternative hypothesis Ha : $\mu$ D  $\neq$ 0