Answer and Step-by-step explanation: The null and alternative hypothesis for this test are:


To test it, use F-test statistics and compare variances of each treatment.
Calculate F-value:



F = 1.8356
The <u>critical value of F</u> is given by a F-distribution table with:
degree of freedom (row): 20 - 1 = 19
degree of freedom (column): 20 - 1 = 19
And a significance level: α = 0.05
= 2.2341
Comparing both values of F:
1.856 < 2.2341
i.e. F-value calculated is less than F-value of the table.
Therefore, failed to reject
, meaning there is <u>no sufficient data to support the claim</u> that sham treatment have pain reductions which vary more than for those using magnets treatment.
Answer:
2(2n - 1)
Step-by-step explanation:
Let x = the number of books Theo has read
Then 4x = four times the number of books Theo has read.
And 4n - 2 = 2 less than four times the number of books Theo has read
But 4n -2 = the number of books Maya has read
Factor the expression
4n - 2 = 2(2n - 1)
The factored expression is 2(2n - 1).
Answer:
It would take the newer pump 4.5 hours to drain the pool
Step-by-step explanation:
Let's investigate first what is the fraction of the job done in the unit of time (hour in this case) by each pump if the work individually:
older pump: if it takes it 9 hours to complete the job, it does
of the job in one hour.
newer pump: we don't know how long it takes (this is our unknown) so we call it "x hours". Therefore, in the unit of time (in one hour) it would have completed
of the total job.
both pumps together: since it takes both 3 hours to complete the job, in one hour they do
of the job.
Now, we can write the following equation about fractions of the job done:
<em>The fraction of the job done by the older pump plus the fraction of the job done by the newer pump in one hour should total the fraction of the job done when they work together.</em> That is in mathematical terms:

and solving for x:
