<span>valid. She used a representative sample
</span>because she correctly found the average and 18,000 is a reasonable number to get for a the problem
First you need to find a common denominator.
20/45x + 9/45x = 87
Combine like terms.
29/ 45x = 87
Multiply both sides by 45/29
x = 3,915 / 29
x = 135
Hope this helps!
Paul : company B
30,000 + 10(2400) = 30,000 + 24,000 = 54,000
Sharla : company C
36,000 + 10(2000) = 36,000 + 20,000 = 56,000
Sharla made more....she made (56,000 - 54,000) = 2,000 more
If the cos A = .83 then the arc cosine of .83 equals the angle
arc cosine (.83) = 33.901 degrees
Similarly, we look up the arc cosine of .55
arc cosine (.55) = 56.633 degrees
NOW we can look up the sine of 33.901 degrees and find it is the
sine of A and it equals 0.55776
the sine of 56.633 degrees = 0.83516 and that is the sine of B