Answer:
B
Step-by-step explanation:
can i get brainliest??????
Answer: x = -4 ; Angle = 60°
Concept:
The given figure is a triangle with 3 arc signs on each angle. This <u>arc sign </u>stands for the corresponding angles are congruent, which in this question, it shows that all three angles are congruent. Sometimes, if the figure has multiple angles and there are different groupings of congruent angles, then we use different numbers of arcs or symbols.
Solve:
<u>Given information</u>
An angle = 3x + 72
Total measure of angles = 180 (triangle angle sum theorem)
Total number of congruent angles = 3
<u>Given expression</u>
Total measure = Total number of congruent angles × An angle measure
<u>Substitute values into the expression</u>
180 = 3 (3x + 72)
<u>Divide 3 on both sides</u>
180 / 3 = 3 (3x + 72) / 3
60 = 3x + 72
<u>Subtract 72 on both sides</u>
60 - 72 = 3x + 72 - 72
-12 = 3x
<u>Divide 3 on both sides</u>
-12 / 3 = 3x / 3

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<u>Find the angle measure</u>
3x + 72 = 3 (-4) + 72 = 
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423.6 is the correct answer
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