Answer:
■ Sales tax: $52.75
■ Cost/Price before ST: $540.99
■ Total Cost/Price including ST: $593.74
Step-by-step explanation:
540.99 x 0.0975
= 52.75
Total
= 540.99+52.75
=593.74
Answer:First you have to add all of the shirts together, which gives you: 40
Since 15 of those are black, then you need to put those 15 over the total number of 40, making it 15/40.
Then you must simplify by the highest number that will go into both, and since that number is 5, it will then go into 15 three times and it will go into 40 eight times.
That leaves you with the answer of: 3/8
Answer:
and 
Step-by-step explanation:
If two equations are given, we can solve one of the equation in terms of single variable and put it in the other equation which will further give the value of x and y.
For the given equations:
Equation:1
Equation:2
Solving equation multiply equation 2 with 4 on both the sides
Equation 3
Subtracting Equation:3 from Equation:1

Putting value of 'y' in Equation:2 which will give the value of x

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.