Answer: Null hypothesis :

Alternative hypothesis :

The test is two-tailed test.
Step-by-step explanation:
A null hypothesis
is defined as
- hypothesis that proposes that there is no difference between particular characteristics of a population.
- It takes ' = ', ' ≤' , '≥'
Alternative hypothesis
is defined as
- hypothesis that proposes that there is a significant difference between particular characteristics of a population.
- It takes ' ≠ ', ' <' , '>'
- If alternative hypothesis is two tailed then we apply two tail test and if alternative hypothesis is left tailed/ right tailed then we apply two left -tailed / right tailed test respectively.
Let p be the proportion of all homeowners have a home security alarm.
As per given, A security expert claims that exactly 19% of all homeowners have a home security alarm.
i.e. Null hypothesis :

Alternative hypothesis :

Here , the alternative hypothesis is two-tailed.
Therefore, the test is two-tailed test.