Answer:
a.1.90 years
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.
In this question:

So

So the correct answer is:
a.1.90 years
Answer:
Speed of wind = 23.63 miles per hour
Plane speed in still air = 260 miles per hour
Step-by-step explanation:
Given:
Time taken with wind = 5 hour
Time taken against wind = 6 hour
Assume;
Speed of wind = s
So,
Speed of Plane with wind = (260 + s) miles per hour
Speed of Plane against wind = (260 - s) miles per hour
Distance = speed x time
So,
(260 + s)5 = (260 - s)6
1,300 + 5s = 1,560 - 6s
11s = 260
s = 23.63 miles per hour
Speed of wind = 23.63 miles per hour
Plane speed in still air = 260 miles per hour
.059, you move the decimal point two times to the left and the other way around when you want to convert into a percent
Well you have to find the lest common factor
8 times 6
6 times 8
They both equal 48 so it would be the vise versa
Answer:
x=90
Step-by-step explanation:
So, since x-20 is the vertical angle directly near 70, we can say:
x-20=70.
if we solve x is 90.
HOPE IT HELPS!!!!!!!!!!!