Answer:
A sample size of 61 will produce a margin of error of 9% with 90% confidence level
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 of the confidence interval is:
For this problem, we have that:
90% confidence level
So , z is the value of Z that has a pvalue of , so .
What sample size will produce a margin of error of 9% with 90% confidence level
This is n when M = 0.09. So
A sample size of 61 will produce a margin of error of 9% with 90% confidence level
Answer:
The hang time is 0.63 seconds
Step-by-step explanation:
We want to find out what the cricket's fall time is and we have the function that describes its height as a function of time.
The cricket is on the ground when its height is equal to zero. Therefore we must equal h to zero and solve the equation for t ..
We take t as a common factor
Then the height is zero when t = 0 and when (10-16t) = 0
At t = 0 seconds the cricket is still on the ground.
Then the cricket is in the air and after 0.63 seconds the cricket falls back to the ground
Answer: the test has 10 multiple-choice questions and 15 Word problems questions.
Step-by-step explanation:
Let x represent the number of multiple-choice questions in the test.
Let y represent the number of Word problems questions in the test.
The total number of multiple-choice and Word problems questions in the test is 25. This means that
x + y = 25
The multiple-choice questions are worth three points and Word problems are worth four points. The test is worth a total of 90 points. This means that
3x + 4y = 90 - - - - - - - - - - -1
Substituting x = 25 - y into equation 1, it becomes
3(25 - y) + 4y = 90
75 - 3y + 4y = 90
- 3y + 4y = 90 - 75
y = 15
x = 25 - y = 25 - 15
x = 10
Answer:
wah
Step-by-step explanation: