Aresearcher wishes to estimate, with % confidence, the population proportion of adults who think congress is doing a good 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 % 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.)

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

1/4 because there is 4 grades.

answer: bearing in mind that a rectangle has a perimeter of length + length + width + width.

step-by-step explanation:

p = perimeter

l = length

x=width

p = 2l + 2x

p = 2(l+x)     < ==== perimeter of the base of the box.