Answer:
The value of the test statistic is -2.64.
Step-by-step explanation:
The test statistic is:

In which X is the sample mean,
is the expected(claimed) mean,
is the standard deviation and n is the size of the sample.
An automobile manufacturer claims that its van has a 40.3 miles/gallon (MPG) rating.
This means that 
After testing 250 vans, they found a mean MPG of 39.9. Assume the standard deviation is known to be 2.4.
This means, respectively, that:

So



The value of the test statistic is -2.64.
Answer:
Horizontal lines are parallel to the x-axis
The answer is the second option
Answer:
c=3d
Step-by-step explanation:
What equation models the data in the table if d = number of days and c = cost? Days Cost 2 6 3 9 5 15 6 18
Answer: An equation is a statement used to show the relationship between variables and shows the equality between two expressions. We want to find the relationship between the number of days and the cost.
Given that:
Days Cost
2 6
3 9
5 15
6 18
Lets take the ratio of days to cost using the first row:

The relationship c = 3d is true for all values of days and cost
point slope form of a line
y-y1 = m(x-x1)
y-7 = -2 (x-1)
if you want it in slope intercept form
y-7 = -2x +2
add 7 to each side
y = -2x +9