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