Answer:
Please see attached picture for full solution.
Sorry, I'm not sure how to do Q7 :(
I can see you come from outside the USA. No insults intended!!
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Anyways, we have to put one side of the ratio and match it to 48.
.
Or even better...
.
MAKE!!
A!!
PROPORTION!!
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So... Let's say 7 is proportional to 48... so 7/5 = 48/x, where x is the number equivalent to ratio of 5.
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Cross multiply!!
<span>.
</span>7x = 240.
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Divide 7 on both sides.
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x = 34 2/7.
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Hope I helped!!
Answer:
x=-4/5
Step-by-step explanation:
8/20=x/-2
simplify 8/20 into 2/5
2/5=x/-2
cross product
5*x=-2*2
5x=-4
x=-4/5
Answer:
The minimum sample size needed is 125.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
The margin of error is:

For this problem, we have that:

99% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
What minimum sample size would be necessary in order ensure a margin of error of 10 percentage points (or less) if they use the prior estimate that 25 percent of the pick-axes are in need of repair?
This minimum sample size is n.
n is found when 
So






Rounding up
The minimum sample size needed is 125.