There is a 95% probability that the true population proportion lies within the confidence interval.
No, it is not. A 99% confidence interval would be wider. Best regards, NS
The Confidence Interval is a particular type of measurement that estimates a population's parameter. Usually, a confidence interval correlates with a percentage. The certain percentage represents how many of the same type of sample will include the true mean. Therefore, we would be a certain percent confident that the interval contains the true mean.
1.96
For a two-tailed interval, they are -1.645 to 1.645
Confidence interval considers the entire data series to fix the band width with mean and standard deviation considers the present data where as prediction interval is for independent value and for future values.
Never!
No, it is not. A 99% confidence interval would be wider. Best regards, NS
if the confidence interval is 24.4 to 38.0 than the average is the exact middle: 31.2, and the margin of error is 6.8
decrease
The Z-value for a one-sided 91% confidence interval is 1.34
The Confidence Interval is a particular type of measurement that estimates a population's parameter. Usually, a confidence interval correlates with a percentage. The certain percentage represents how many of the same type of sample will include the true mean. Therefore, we would be a certain percent confident that the interval contains the true mean.
4.04%
1.96
1.0966
For a two-tailed interval, they are -1.645 to 1.645
The confidence interval will be Pi+-z*spz5%= 1.6449Pi = x/nSp = Sqrt(Pi(1-Pi)/n)Pi ~= 0.5694Sp = Sqrt(.5694*0.4306/144) ~= 0.0413Pi - 0.0679 < p < Pi + 0.06790.5016 < p < 0.6373You can do this on your TI-83/84 with 1-PropZInt (Stat->Tests->A)
Estimated p = 75 / 250 = 0.3 Variance of proportion = p*(1-p)/n = 0.3(0.7)/250 =0.00084 S.D. of p is sqrt[0.00084] = 0.029 Confidence interval: phat-zval*sd = 0.3 - (1.96)(0.028983) phat-zval*sd = 0.3 + (1.96)(0.028983) Confidence interval is ( 0.2432 , 0.3568 )