<span> value
Weighted mean average = ---------------------------
number of brands
value = mean price of computers from Store
#1 * number of brands from store #1 + mean price of computers from store #2 * number of brands from store #2
value = $799.99 * 2 + $679.99 * 4 = $4,319.94
number of brands = 2 + 4 = 6
weighted average = $4,319.94 / 6 = $ 719.99
Answer: option b. $719.99
</span>
Given the triangle
PQR
with points
P(8,0)
Q(6,2)
R(-2,-4)
And the triangle
P'Q'R'
with points
P'(4,0)
Q'(3,1)
R'(-1,-2)
Part A. Scale factor
Using the vertex
P( 8, 0)
P'(4,0)
the dilatation factor is given by

The triangle has a dilatation factor of 1/2
Part B:
P''Q''R'' after using P'Q'R' reflected about the y axis
to make a reflection over the y axis
coordinates (x,y) turn into coordinates (-x,y)
as follows



Then triangle P''Q''R'' has coordinates
P''(-4,0)
Q''(-3,1)
R''(1,-2)
Part C:
PQR is congruent to P''Q''R''?
Congruent triangles are triangles that have the same size and shape. This means that the corresponding sides are equal and the corresponding angles are equal.
Then the triangles are not congruent
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.