55. if a test statistic falls in the critical region the null hypothesis is a) rejected b) not rejected c) it depends d) accepted

Option a) Rejected              

Step-by-step explanation:

We define critical region as:

It is also known as the rejection region.It is the region where the null hypothesis is rejected.Thus, if our calculated test statistic lies in the critical region, we fail to accept the null hypothesis and reject it.For right tailed test: The critical region is the values greater than the critical value.For left tailed test: The critical region is the values less than the critical value.The critical region for two tailed test is the value apart from the range of critical values.

Thus,

If a test statistic falls in the critical region the null hypothesis is rejected.

It creates dogx^2 and then flip your answer and multiply by 2

Could you make it more clear?