Answer:
-12
Step-by-step explanation:
<u>Step 1: Substitute</u>
ab -> -4 for a and 3 for b
(-4) * (3)
<em>-12</em>
Answer: -12
The daily newspaper stand had began with 87 copies.
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
Answer: 22.5 minutes
Step-by-step explanation: On Monday Georgia practiced for 3/4 of an hour and on Tuesday she practiced for 3/8 of an hour. The difference between those two is 3/8 of an hour and when you take 3/8 of 60 minutes you get 22.5 minutes