A $30 shirt is marked, "Get 25% off." What is the sale price of the shirt?
2 answers:
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Answer:
P-value
First we find the degrees of freedom given by:
Since is a two-sided test the p value would be:
Step-by-step explanation:
Data given and notation
represent the sample mean
represent the sample standard deviation
sample size
represent the value that we want to test
represent the significance level for the hypothesis test.
z would represent the statistic (variable of interest)
represent the p value for the test (variable of interest)
State the null and alternative hypotheses.
We need to conduct a hypothesis in order to check if the mean differs from 4.73, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
Since we know don't the population deviation, is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:
(1)
t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".
Calculate the statistic
We can replace in formula (1) the info given like this:
P-value
First we find the degrees of freedom given by:
Since is a two-sided test the p value would be: