Question

According to the WHO, the “incubation period” means the time between catching the virus and beginning to have symptoms of the disease. Most estimates of the incubation period for COVID-19 range from 1-14 days, most commonly around five days.

Pretend you are a statistician and you suspect the mean incubation period is actually longer than 5 days. Suppose you gathered some new data and want to test your hypotheses at a significance level of 5%.

Questions:

1. State the null and alternative hypotheses in words and in symbols.

2. State your conclusion if

a) p-value is 0.02

b) p-value is 0.07.

Answer 1

Null hypothesis:

Ho: The incubation period is 5 days.

Alternative hypothesis:

H1: The incubation period is longer than 5 days.

Decision Rule: Reject Ho if alpha > pvalue

a) pvalue=0.02

Here alpha = 0.05> pvalue =0.02.We reject Ho at 5% level of significance.

The data shows that the mean incubation period is longer than 5 days

b) pvalue=0.07

Here alpha=0.05< pvalue=0.07. We fail to reject Ho at 5% level of significance.

The data does not support that the mean incubation period is longer than 5 days. It shows mean incubation period is 5 days