An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 45 hours. If a sample of 35 bulbs has an average life of 710 hours, find a 96% confidence interval for the population mean of all bulbs produced by this firm.
Accepted Solution
A:
Answer:[693,38:725,62]hsStep-by-step explanation:Hello!Your study variable is X: the lifespan of a light bulb. This variable is said to have an approximately normal distribution.X≈N(μ;σ²)Wereμ= populatiom meanσ= 45 hs standard deviationA sample of n= 35To estimate the population mean with a confidence interval you have to use the Z statistic:X{bar} ± [tex]Z_{1-\alpha /2}[/tex]*(σ/√n)[tex]Z_{1-\alpha /2} = Z_{0.98} = 2.054[/tex]710 ± 2.054*(45/√35[693,38:725,62]hsI hope you have a SUPER day!