In: Statistics and Probability
b. Interpret the 95% confidence interval you constructed.
Solution :
Given that,
n = 100
x = 26
Point estimate = sample proportion = = x / n = 26/1000.26
1 - = 1- 0.26 =0.74
At 95% confidence level the z is ,
= 1 - 95% = 1 - 0.95 = 0.05
/ 2 = 0.05 / 2 = 0.025
Z/2 = Z0.025 = 1.96 ( Using z table )
Margin of error = E = Z/2 * ((( * (1 - )) / n)
= 1.96 (((0.26*0.74) /100 )
E = 0.0860
A 95% confidence interval for population proportion p is ,
- E < p < + E
0.26-0.0860< p < 0.26+0.0860
0.1740< p < 0.3460
The 95% confidence interval for the population proportion p is : 0.1740,0.3460