An electrical manufacturing firm producing molded case circuit breakers claims that their breakers will last, on average, 30 years with a variance of 12.5 years . If five of these breakers have a...

An electrical manufacturing firm producing molded case circuit breakers claims that their breakers will last, on average, 30 years with a variance of 12.5 years . If five of these breakers have a variance of 10.89 years, construct a 98% confidence interval for the variance and decide if the manufacturing firm’s claim that a variance of 12.5 years is valid. Assume the population of the breaker lives to be approximately normally distributed.