what sign of a null hypothesis must always include?
a.
not equal
b.
greater
c.
smaller
d.
equality

Option d - Equality

Step-by-step explanation:

To find : What sign of a null hypothesis must always include?

Solution :

The Null hypothesis is defined as a statement about the population that either is believed to be true or is used to put forth an argument unless it can be shown to be incorrect beyond a reasonable doubt.

The Null hypothesis represent by

always has a symbol with an equal in it.

Therefore, Option d is correct.

Equality sign of a null hypothesis must always include.