Please help 4 b + 13 equals 57
1 answer:
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Answer:
<u>Group the Variable's</u>:
2 x - 5 + 7 y - 3 = 9 x - 1 - y -8
2x -9x + 7y +y = -1 -8 +5 + 3
-7x + 8y = -1
<u><em>From this find x and y</em></u>
<u>For X</u>
-7x + 8y = -1
-7x = -1 -8y
7x = 8y + 1
x = (8y +1)/7
<u>For Y</u>
-7x + 8y = -1
8y = -1 +7x
y = (7x -1)/8
Answer:
The 90% confidence interval for the mean score of all takers of this test is between 59.92 and 64.08. The lower end is 59.92, and the upper end is 64.08.
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 , so
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.
The lower end of the interval is the sample mean subtracted by M. So it is 62 - 2.08 = 59.92
The upper end of the interval is the sample mean added to M. So it is 62 + 2.08 = 64.08.
The 90% confidence interval for the mean score of all takers of this test is between 59.92 and 64.08. The lower end is 59.92, and the upper end is 64.08.