Answer:
75 degrees.
Step-by-step explanation:
The total number of degrees in a triangle is 180 degrees therefore you can take the sum of the other 2 angles in the triangle and take that number and subtract it from 180.
1). 30+75=105
2).180-105=75
3). using the Side, Side, Side geometry rule, this means that both triangles are the same for all angles and side lengths
4). using the Alternative angle rule, the rule that say that a line that intersects 2 parallel lines forms 4 pairs of similar angles
5). therefore angle ABC is the same as angle BCD
6). Angle ABC was determined to be 75 degrees therefore angle BCD is also 75 degrees
17.5 i think, i mean dont hold it against me if not but i multiplied 2.5 and 7 sooo
Answer:
(4,5)
Step-by-step explanation:
To find the x coordinate of the midpoint, average the x coordinates of the endpoints
(1+7)/2 = 8/2 = 4
To find the y coordinate of the midpoint, average the y coordinates of the endpoints
(2+8)/2 = 10/2 = 5
Answer:
C. I think
Step-by-step explanation:
Answer:
The minimum sample size needed is 39.
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 
.
That is z with a pvalue of 
, so Z = 2.575.
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.
Assuming that the standard deviation of the number of hours is 120 hour
This means that 
The minimum sample size needed in order to construct a 99% confidence interval for the mean number of hours of flight time of all such pilots, to within 50 hours, is about?
The minimum sample size needed is n.
n is found when 
So
Rounding up
The minimum sample size needed is 39.
