Answer:
A sample size of 385 is needed.
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 = 1.96.
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.
You feel that a reasonable estimate of the standard deviation is 10.0 hours.
This means that 
What sample size is needed so that the expected margin of error of your estimate is not larger than one hour for 95% confidence?
A sample size of n is needed. n is found when M = 1. So
Rounding up:
A sample size of 385 is needed.
I believe the answer would be 90.
Answer:
18v-32
Step-by-step explanation:
Answer:
(x, y) = (6, 1) is the solution
Step-by-step explanation:
Each of the equations is written in "slope-intercept" form:
y = mx + b . . . . . . . . where m is the slope and b is the y-intercept
<u>First equation</u>
The y-intercept is +7 and the slope is -1. That means the line goes down 1 unit for each unit it goes to the right. It will go through the points (0, 7) and (7, 0).
<u>Second equation</u>
The y-intercept is -2 and the slope is 1/2. That means the line goes up 1 unit for each 2 units it goes to the right. It will go through the points (0, -2) and (4, 0).
The lines will intersect at the point (6, 1), which is the solution found by graphing.
B its 43.96 in :) hope this helped
