Posted by Joey on Saturday, March 28, 2009 at 10:58pm.
Determine the sample size required to estimate a population proportion to within 0.032 with 95.7% confidence, assuming that you have no knowledge of the approximate value of the sample proportion.
Sample Size =
B. Repeat part the previous problem, but now with the knowledge that the population proportion is approximately 0.33.
Sample Size =
i don't understand how you can do this without the margin or error.

statistics  MathGuru, Saturday, March 28, 2009 at 11:35pm
Try this formula:
n = [(zvalue)^2 * p * q]/E^2
Note: n = sample size needed; .5 for p and .5 for q are used if no value is stated in the problem. E = maximum error, which is 0.032. Zvalue is found using a ztable (for 95.7% confidence).
For B, use 0.33 for p and 0.67 for q.
Note: q = 1  p
I'll let you take it from here.

statistics  Amelia, Wednesday, November 16, 2011 at 10:00pm
Allen's hummingbird (Selasphorus sasin) has been studied by zoologist Bill Alther.† Suppose a small group of 11 Allen's hummingbirds has been under study in Arizona. The average weight for these birds is x = 3.15 grams. Based on previous studies, we can assume that the weights of Allen's hummingbirds have a normal distribution, with σ = 0.30 gram.
Find the sample size necessary for an 80% confidence level with a maximal error of estimate E = 0.09 for the mean weights of the hummingbirds. (Round up to the nearest whole number.)
Answer This Question
Related Questions
 Statistics  Determine the sample size necessary to estimate a population ...
 Statistics  In a prior sample of U.S. adults, the Center for Disease Control (...
 Statistics  Find the minimum sample size that should be chosen to assure that ...
 statistics  2. Assume that the population proportion of adults having a college...
 statistics  An IQ is designed so that the mean is 100 and the standard ...
 Elementary Statistics  1) Construct a confidence interval of the population ...
 Data Analysis  A) An insurance company wants to estimate the proportion of ...
 Stats  2) Find the minimum sample size that should be chosen to assure that the...
 statistics  The Democrat and Chronicle reported that 25% of the flights ...
 statistics  What sample size is required from a very large population to ...
More Related Questions