Answer:
c. H0: μ = 23.3 Ha: μ < 23.3
Step-by-step explanation:
The null hypothesis is related to the expected value.
A few years ago the average age of online consumers was 23.3 years.
This means that the null hypoteshis, that is, H0, is μ = 23.3.
The alternate hypothesis is related to the question made.
Is there sufficient evidence to show that the mean age of online consumers has decreased?
The question is if the age of 23.3 has decreases. This means that the alternate hypothesis, that is, Ha, is μ < 23.3.
So the correct answer is:
c. H0: μ = 23.3 Ha: μ < 23.3