Stats 7-2 Estimating population Proportion

margin of error = E

the maximum likelihood of difference

critical value ex Zα/₂

the number on the borderline separating sample stats that are likely to occur from those that are unlikely.

c i = 85% +/-E p^-E<p<p^+E

.85-.022 or .85+.22 = .828, .872

CI = confidence interval or interval estimate. 0.828 < p < 0.872

a range or interval of values used to estimate the true value of a pop parameter.

point estimate

a single value -or point- used to approximate a population parameter - best estimator is a sample proportion or p^

how to find the E E = Z∞/2√(p^q^/n)

multiply critical value and the standard deviation of sample proportions - don't forget the square

when estimate p^ is NOT known, use this formula to find the sample size needed

n= [(Z∞/₂)²*0.25)] /E² means. sample size = critical value, squared, times .025 divided by Margin of Error squared

when estimate p^ is known use this formula to find the sample size needed

n= [(Z∞/₂)²*p^*q^)] /E² means. sample size = critical value squared times probability times probably not divided by Margin of Error squared

confidence level , degree or confidence or confidence coefficient = 1-∞ = 95% or .95

success rate of the procedure. Probability that the C.I. actually does contain the population parameter, assuming that the estimation process is repeated a large number of times.

sample proportion p^

unbiased p^ and most consistent