Answer:
Margin of error of 0.0485 hours.
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.
In this question:
The margin of error is of:
Margin of error of 0.0485 hours.
Well, since 3/15 can be simplified to 1/5 by dividing the top and the bottom by 3, you would just need to find the decimal of 1/5 which is much more commonly recognized. it's .2 (becasue 1/10 would be .1 and 1/5=2/10 so .1x2=.2)
Answer:
32.625 m
Step-by-step explanation:
You have the proportion ...
18 cm : ___ m = 22.4 cm : 40.6 m
This can be rearranged to ...
___ m/(18 cm) = (40.6 m)/(22.4 cm)
Multiplying by 18 cm gives ...
___ m = (40.6 m)·(18/22.4)
___ m = 32.625 m
