Answer:
It would be 1.5m+4 is greater than or equal to 7. This is because 1.5m is the regular rate of growth, plus the 4cm already grown. She wants the hair to be no shorter than 7cm. So, the 15m+4 has to be greater than the 7cm.
Step-by-step explanation:
Answer:
Since the calculated values is lower than the critical value we have enough evidence to reject the null hypothesis at the significance level of 2.5% and we can say that the true mean is lower than 36 years old
Step-by-step explanation:
Data given
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.
t would represent the statistic (variable of interest)
represent the p value for the test (variable of interest)
System of hypothesis
We need to conduct a hypothesis in order to check if the true mean is less than 36 years old, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
The statistic is given by:
(1)
And replacing we got:
Now we can calculate the critical value but first we need to find the degreed of freedom:
So we need to find a critical value in the t distribution with df =21 who accumulates 0.025 of the area in the left and we got:
Since the calculated values is lower than the critical value we have enough evidence to reject the null hypothesis at the significance level of 2.5% and we can say that the true mean is lower than 36 years old