Site pages
Current course
Participants
General
18 February - 24 February
25 February - 3 March
4 March - 10 March
11 March - 17 March
18 March - 24 March
25 March - 31 March
1 April - 7 April
8 April - 14 April
15 April - 21 April
22 April - 28 April
3.6.Interval Estimators - Case 2
Unit 3 - Estimation
3.6.Interval Estimators
3.6.2.Case 2: (1- α ) % Interval estimates for population proportion is given by,
Where : p is the sample proportion and
The maximum error E given by:
If the sample size is 64 individuals, and the percentage of female individuals in the sample is 35%, determine using a significance level of 1%, the corresponding confidence interval for the proportion of the female in population.
Solution
α = 0.01;
1 − α = 0.99;
zα/2 = 2.575.
Example 2
In a sample of 400 selected at random, a sample mean of 50 was obtained. Determine the confidence interval with a confidence level of 97% for the average population.
Solution:
Example 3
With the same confidence level, what minimum sample size should it have so that the interval width has a maximum length of 1?
Solution
Last modified: Monday, 12 September 2011, 10:45 AM