A researcher wishes to estimate, with 9999% confidence, the population proportion of adults who think Congress is doing a goo
d or excellent job. Her estimate must be accurate within 44% of the true proportion. (a) No preliminary estimate is available. Find the minimum sample size needed. (b) Find the minimum sample size needed, using a prior study that found that 2222% of the respondents said they think Congress is doing a good or excellent job. (c) Compare the results from parts (a) and (b). (a) What is the minimum sample size needed assuming that no prior information is available? nequals=nothing (Round up to the nearest whole number as needed.)
1 answer:
Answer:
a: 1037 is the minimum sample size needed
b: 712 is the minimum sample size needed
Step-by-step explanation:
We need to use the formula for minimum sample size of a proportion when a sample proportion is known.
The level of confidence is 99%, which has a corresponding z-value of 2.575.
We know the desired error is 4%, or 0.04.
Part a: We have no prior estimate. See attached photo for calculation
Part b:
We know p-hat = 0.22. Therefore q-hat = 1 - 0.22 = 0.78
See the attached photo for the calculation of the minimum sample size
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Answer:
D
Step-by-step explanation:
We need the formula for arc length (in radians) to solve this problem. The formula is:
Where
s is the arc length
r is the radius of the circle
is the intercepted angle
In this diagram, we can see that is beign intercepted by the big arc with measure 20 cm. So arc length, s, is 20
Also, if we look, we see that the radius is 5 cm, so r = 5
Now, we substitute into formula and find :
This is given in radians, so is 4 radians
D is the correct answer choice.
Answer:
The answer is D
That's the only equation will get us one point