Speed was increased 20% to 48 mph. What was the speed before the increase
1 answer:
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Answer:
120 distinct results are possible if no child is to receive more than one gifts.
Step-by-step explanation:
When the order is not important, we use the combination formula:
is the number of different combinatios of x objects from a set of n elements, given by the following formula.
The order is said to be not important if for example, John receiving the Buffalo Bills jersey and then Laura receiving the Cleveland Browns jersey is the same as Laura receiving the Cleveland Browns jersey before John receives the Buffalo Bills jersey.
In this problem, we have that:
Combinations of 7 from a set of 10 elements. So
120 distinct results are possible if no child is to receive more than one gifts.
Answer:
- 15
Step-by-step explanation:
Using the z-distribution and the formula for the margin of error, it is found that:
a) A sample size of 54 is needed.
b) A sample size of 752 is needed.
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 z-score that has a p-value of .
The margin of error is of:
90% confidence level, hence, z is the value of Z that has a p-value of
, so
.
Item a:
The estimate is .
The sample size is <u>n for which M = 0.03</u>, hence:
Rounding up, a sample size of 54 is needed.
Item b:
No prior estimate, hence
Rounding up, a sample of 752 should be taken.
A similar problem is given at brainly.com/question/25694087