Question

And a survey of 500 households 23% say that they have a dog as a pet the standard deviation is 2% determine an interval that if I need to contain the 95% of all households who has a dog as a pet

Answer 1

(114.123, 115.877)

Explanation:

Given that :

Sample size (n) = 500

Mean = 23% of 500 = 115

Standard deviation (s) = 2% of 500 = 10

α = 95%

Zcritical at 95% = 1.96

Confidence interval = Mean ± Error

Error = Zcritical * standard deviation /sqrt (n)

Error = 1.96 * 10/sqrt(500)

Error = 0.8765386

Lower boundary : 115 - 0.8765386 = 114.1234614

Upper boundary : 115 + 0.8765386 = 115.8765386

(114.123, 115.877)