Using algebra, I obtained that r=5
Answer:
c=5
Step-by-step explanation:
Simplify both sides of the equation.
4(6c+5)−2(3c−5)=120
(4)(6c)+(4)(5)+(−2)(3c)+(−2)(−5)=120(Distribute)
24c+20+−6c+10=120
(24c+−6c)+(20+10)=120(Combine Like Terms)
18c+30=120
Subtract 30 from both sides.
18c+30−30=120−30
18c=90
Divide both sides by 18.

c=5
hope this helps... :/
Answer:
554 executives should be surveyed.
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 Z-table as such z has a p-value 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.
Standard deviation of 3 hours.
This means that 
The 95% level of confidence is to be used. How many executives should be surveyed?
n executives should be surveyed, and n is found with
. So






Rounding up:
554 executives should be surveyed.
Answer:
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