Answer:
The null and alternative hypothesis is
and
respectively.
Step-by-step explanation:
Consider the provided information.
If there is no statistical significance in the test then it is know as the null which is denoted by
, otherwise it is known as alternative hypothesis which denoted by
.
Consider the statement:
Test to see whether the mean tree planting time differ from two hours.
The null hypothesis is: 
Therefore, the alternative hypothesis is: 
Thus, the null and alternative hypothesis is
and
respectively.