Answer:
$8.85
Step-by-step explanation:
This a question of direct variation, so we can make out a relationship between the two factors. 12 is 2/3 of 18, so the cost of 12 would also be 2/3 of the cost of 18. We can now make an equation to solve.
A new cream was developed to reduce the irritation caused by poison ivy. To test the effectiveness, researchers put an ad online
2 answers:
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Answer:
The margin of error for the 90% confidence interval is of 0.038.
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:
To this end we have obtained a random sample of 400 fruit flies. We find that 280 of the flies in the sample possess the gene.
This means that
90% confidence level
So , z is the value of Z that has a pvalue of
, so
.
Give the margin of error for the 90% confidence interval.
The margin of error for the 90% confidence interval is of 0.038.