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:
the multiplicity is 4
Step-by-step explanation:
The graph shows a root at x = -2 that has a multiplicity of 2. You know the multiplicity is even, because the graph does not cross the x-axis. The multiplicity is 2 because the general shape of the graph in that area matches that of a quadratic (parabola).
The multiplicity of the root at x=4 is also an even number, because the x-axis is not crossed. However, the graph is significantly flatter at that point (than at x=-2), meaning the multiplicity is greater than 2. It is at least 4.
When we draw a graph with a multiplicity of 6 at x=4, we find the ratio of the peaks near x=-4 and x=0 to be different from that shown here. The suggests that the multiplicity of the root at x=4 is exactly 4.
