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.
The y-intercept is obtained when we equate x to 0, where x is the number of songs bought. Thus, before buying any songs, $6 have to be paid. This is the cost of joining the the music club. The second statement is true.
The length of 
is given by the relationship between the similar triangles
ΔABD and ΔBDC.
- = <u>80</u>
Reasons:
The given parameters are;
The altitude of triangle ΔABD = 
The hypotenuse of formed right triangle = 
The length of AD = 8
Length of BD = 24
Whereby ΔABD is a right triangle
We have;
ΔABD is similar to ΔBDC
Therefore, by similar triangle proportional sides relationship, we have;
Which gives;
= 
Therefore;
Which gives;
Learn more about similar triangles here:
brainly.com/question/4618367
Answer:
try restarting it or re downloading
