Sample Proportion & Standard Error

Related BrainMass Solutions

• Calculating sample Size

  This is a two tailed test since we are testing whether sample proportion will not differ from the true population proportion σp=standard error of proportion=√(pq/n) The maximum value of standard error of proportion for any

• Estimate standard error of a sample proportion

  237059 Estimate standard error of a sample proportion Of 2003 adults interviewed, 54% said yes, 42% said no, and 4 % no opinion. Find the estimated standard error for a sample proportion answering yes, and interpret?

• Hypothesis Test: What is the confidence interval for the true proportion of students who support a fee increase?

  This is a problem for calculation of confidence interval for proportion First calculation the sample proportion P=870/1100=0.7909 Then calculate the standard error Standard error = (pq/n)^0.5 Where p=sample proportion q=1-p n=sample size Standard

• Proportions - Standard error and confidence interval

  A sample of 400 voters reveals that 300 would support her in the November election. Estimate the value of the population proportion. Compute the standard error of the proportion.

• Sample Size, Margin of error

  Sample size (proportions): confidence interval= 95% proportion =p= Known = 0.55 Error= ±z*sp= 0.01 or 1% where sp=standard error of proportion=square root of (pq/n) Thus we have to ensure that Z* sp < 1%

• Sampling Error when Estimating a Population Proportion

  The formula for the standard error of contains a ratio with n, the sample size, in the denominator. This means that as n increases, the standard error decreases.

• Sample size for estimating population proportion

  proportion(p))/ standard error (s p)= 1.9600 or z=(5%/s p)= 1.9600 since sample proportion-population proportion(p)= 5% or 0r s p= 0.025510 =5%/1.96 or s p=standard error of proportion= square root of pq/n= 0.025510

• Proportions

  Mean of the sampling distribution of proportion is the population proportion p= 48.00% Standard error of p is σp=standard error of proportion=√(pq/n) p= 48.00% q=1-p= 52.00% n=sample size

• Sample Size

  This is a two tailed test since we are testing whether sample proportion will not differ from the true population proportion σp=standard error of proportion=√(pq/n) The maximum value of standard error of proportion

• Sample Distribution Scenario Questions

  If past information shows a standard deviation of 7 months, what size sample should be taken so that at 95% confidence the margin of error will be 2 months or less?