Answer:
A one-sided, two-sample t-test
Step-by-step explanation:
In the context, the values of the population standard deviations are not provided, therefore we have to use the two sample t tests for the difference between the two population means. This claim for the hypothesis or the alternative hypothesis is given as the average selling price is more for the first group of the sample size of 21 as compared to the other group of the sample size of 87. Therefore, we perform an one sided test or the upper tailed test.
Slope is equal to the change in y over change in x, or rose over run m= 1/3
Answer:
The correct option is D.
Step-by-step explanation:
The linear regression equation is in the form of

Where,


The formula of r is
![r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n(\sum x^2)-(\sum x)^2][n(\sum y^2)-(\sum y)^2]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7Bn%28%5Csum%20xy%29-%28%5Csum%20x%29%28%5Csum%20y%29%7D%7B%5Csqrt%7B%5Bn%28%5Csum%20x%5E2%29-%28%5Csum%20x%29%5E2%5D%5Bn%28%5Csum%20y%5E2%29-%28%5Csum%20y%29%5E2%5D%7D%7D)
The values are

Using above formula, we get

Therefore option D is correct.
Answer:
45 mph
Step-by-step explanation:
This is a really good question to know the answer to. It is tricky and a bit indirect (which means you have to find something else before you can find the speed of the car.)
Let's keep track of what he does in the time allotted.
How far does Joe go in 5 minutes? That's the amount of time he's on the road before she is.
convert 5 minutes into hours. 5 minutes * 1 hour / 60 minutes = 1/12 of an hour
d = r*t
r = 30 km/hour
t = 1/12 hour
d = 30 km/hr * 1/12 hour = 2.5 km
Now she's about to start. She wants to catch him in 10 minutes
d = r*t
r = x mph
t = 10 minutes = 10 minutes * 1 hour * 60 minutes = 1/6 of an hour.
How far does he go in the 10 minute time?
d = 30 * 1/6 = 5 km
What is his total distance
5 km + 2.5 km = 7.5 km
Finally how fast does she need to go to catch him
d = 7.5 km
r = ? This is what you are trying to find
t = 1/6 of an hour
d = r*t
7.5 km = r * (1/6)hour divide by 1/6 hour
7.5 km // 1/6 hour = r
r = 7.5 * 6 = 45 mph
4/3
you do y2-y1 divided by x2-x1
so 4-0 divided by 3-0 which gets you 4/3