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:
You would be required to pay $587.50
Step-by-step explanation:
Divide $1762.50 by three:
You get $587.50
To find how much you have left:
Subtract 587.50 from 668.72:
You'd be left with
$81.22
Answer:
40
Step-by-step explanation:
4x
4(10)
Answer: 9
Step-by-step explanation:
Since the percent is decaying, you subtract 3.4 from 100, which gets you 96.6
200(0.966)^9 gets you 146.5 which is less than 150
Answer:
expansion
Step-by-step explanation:
I believe that the biggest reason for the general upward trend in the stock price is expansion. Amazon has expanded their company immensely over the last 5 years. They have also expanded into different markets such as drones, gaming, cloud streaming, video streaming, etc. All of these expansions and acquisitions have been incredibly profitable for Amazon and therefore reflect on the stock price. This also gives investors faith that the future of the company will continue growing which causes them to buy more stocks and therefore increase the price.
