91Ó°ÊÓ

The claim is that mean is bigger than$50\%$

The null hypothesis statement states that the population value is equal to the claim value:

$H_0:\mathrm{μ}<50$

The null hypothesis or the alternative hypothesis is the claim. The null hypothesis asserts that the population means equals the value specified in the claim. If the claim is the null hypothesis, then the alternative hypothesis statement is the inverse of the null hypothesis.

$H_1:\mathrm{μ}>50$

$\mathrm{μ}$denotes the average percentage of purchases for which an alternative supply provided lower prices.

Given:

Random, independent ($10\%$condition), and Normal/ Large samples are the three conditions.

Random: Satisfied because the sample was chosen at random.

Independent: Satisfied, because the sample of $25$invoices represents less than $10\%$of the total population of invoices.

Normal/large sample size: Not happy because the sample size of $25$invoices is small and the distribution is skewed (as the highest bar in the histogram is to the right in the histogram).

Because the Normal/Large sample condition is not met, a hypothesis test for the population mean is not appropriate.