
we can rewrite it as

we can see that 1/4 is in multiple in both terms
so, we can factor it out
so, we get
..............Answer
Answer:
C 117
Step-by-step explanation:
<2 = 63
<4 = <2 vertical angles
<4 + <7 = 180
63 + <7 = 180
subtract 63 from each side
<7 = 117
Answer:
0.35 :)
Step-by-step explanation:
Answer:
a)
90% confidence interval for the mean grading time of all composition papers.
(12.47981 , 13.52019)
b)
Appropriate inequality
The interval is ( 12.47981 < μ < 13.52019)
Step-by-step explanation:
<u><em>Explanation</em></u>:-
a)
Given sample size 'n' = 40
Mean of the sample = 13 minutes
standard deviation = 2 min
level of significance = 0.10 or 90%
90% confidence interval for the mean grading time of all composition papers.


( 13 - 0.52019 , 13 + 0.52019)
(12.47981 , 13.52019)
b)
The interval is ( 12.47981 < μ < 13.52019)
Answer:
sin(x) = 5/13
cos(y) = 5/12
Therefore, sin(x) = cos(y)
Step-by-step explanation:
Trig ratios:

where
is the angle, O is the measure of the side opposite the angle, A is the measure of the side adjacent to the angle and H is the hypotenuse, of a right triangle
We have been given the measures of the two legs, so we can find the measure of the hypotenuse by using Pythagoras' Theorem 
(where a and b are the legs and c is the hypotenuse of a right triangle)

Now we can use the trig ratios:


Therefore, sin(x) = cos(y)