Answer:
k = 11
Step-by-step explanation:
Given the points are collinear then the slopes between consecutive points are equal.
Using the slope formula
m =
with (x₁, y₁ ) = (5, 1) and (x₂, y₂ ) = (1, - 1)
m = =
=
Repeat with another 2 points and equate to
with (x₁, y₁ ) = (1, - 1) and (x₂, y₂ ) = (k, 4)
m = , then
=
( cross- multiply )
k - 1 = 10 ( add 1 to both sides )
k = 11
Answer:
Step-by-step explanation:
Answer:
Critical value: z = 1.28
The 80% confidence interval for the mean repair cost for the washers is between $46.487 and $82.033.
Step-by-step explanation:
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of
So it is z with a pvalue of 1-0.1 = 0.9, so z = 1.28
Now, find the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
So
The lower end of the interval is the mean subtracted by M. So 64.26 - 17.773 = $46.487.
The upper end of the interval is M added to the mean. So 64.26 + 17.773 = $82.033.
The 80% confidence interval for the mean repair cost for the washers is between $46.487 and $82.033.