Calculate the confidence interval in R You have ordered 10 b

Calculate the confidence interval in R: You have ordered 10 bags of cement, which are supposed to weigh 94 kg each. The average weight of the 10 bags is 93.5 kg. Assuming that the 10 weights can be viewed as a realization of a random sample from a normal distribution with unknown parameters, construct a 95% confidence interval for the expected weight of a bag. The sample standard deviation of the 10 weights is 0.75.

Solution

> se <- 0.75/ sqrt(10)

> CIL <- 93.5 - qt((100+95)/200, 10-1)*se

> CIH <- 93.5 + qt((100+95)/200, 10-1)*se

> CIL

[1] 92.96348

> CIH

[1] 94.03652

95 %CI =   ( 92.9635, 94.0365)