Answer:
The critical value is T = 1.895.
The 90% confidence interval for the mean repair cost for the washers is between $48.159 and $72.761
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 8 - 1 = 6
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 6 degrees of freedom(y-axis) and a confidence level of
. So we have T = 1.895, which is the critical value.
The margin of error is:

In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 60.46 - 12.301 = $48.159
The upper end of the interval is the sample mean added to M. So it is 60.46 + 12.301 = $72.761
The 90% confidence interval for the mean repair cost for the washers is between $48.159 and $72.761
Answer:
fish=3,5,15
snails=1,4,4
Step-by-step explanation:
Answer:
x = 6
Step-by-step explanation:
Step 1: Write equation
75 - 3.5x - 4x = 4x + 6
Step 2: Solve for <em>x</em>
- Combine like terms: 75 - 7.5x = 4x + 6
- Add 7.5x on both sides: 75 = 11.5x + 6
- Subtract 6 on both sides: 69 = 11.5x
- Divide both sides by 11.5: 6 = x
- Rewrite x = 6
Step 3: Check
<em>Plug in x to verify it's a solution.</em>
75 - 3.5(6) - 4(6) = 4(6) + 6
75 - 21 - 24 = 24 + 6
54 - 24 = 30
30 = 30
Answer:
$32.30
Step-by-step explanation:
19x.30 (to find the 30%)
5.7 needs to be take off of the second shirt.
19 (the first shirt) + (19-5.7) = $32.3