Well,
As we can see, the only difference is that the parentheses have moved.
This is an example of the associative property. It is specifically of multiplication, because products are used in this case.
Just as a test, let's see whether they are really equal.
Following PEMDAS, we get:
(2*4)7 = 2(7*4)
(8)7 = 2(28)
56 = 56
They are equivalent.
Answer:
d. t distribution with df = 80
Step-by-step explanation:
Assuming this problem:
Consider independent simple random samples that are taken to test the difference between the means of two populations. The variances of the populations are unknown, but are assumed to be equal. The sample sizes of each population are n1 = 37 and n2 = 45. The appropriate distribution to use is the:
a. t distribution with df = 82.
b. t distribution with df = 81.
c. t distribution with df = 41.
d. t distribution with df = 80
Solution to the problem
When we have two independent samples from two normal distributions with equal variances we are assuming that
And the statistic is given by this formula:
Where t follows a t distribution with
degrees of freedom and the pooled variance
is given by this formula:
This last one is an unbiased estimator of the common variance
So on this case the degrees of freedom are given by:

And the best answer is:
d. t distribution with df = 80
Answer:
the artist cuts off 10 inches of ribbon in total
Step-by-step explanation:
2.5 × 4 = 10
Answer:
4/9
Step-by-step explanation:
To add or subtract with powers, both the variables and the exponents of the variables must be the same. You perform the required operations on the coefficients, leaving the variable and exponent as they are.