# You measure the lifetime of a random sample of 64 tires of a certain brand. Suppose that the lifetimes for tires of this brand follow a normal distribution, with unknown mean μ and standard deviation σ = 5 kg. What is the 99% confidence interval?

##### 1 Answer

Apr 7, 2017

Population mean lies in between

#### Explanation:

let the Sample mean be

Sample Standard Deviation

Sample size

Then -

Standard Error

Population Mean

#mu=barx+-(zxxSE)#

#mu=barx+-(2.58xx0.625)#

#mu=barx+-1.6125#

Population mean lies in between