An industrial plant claims to discharge no more than 1000 ga

An industrial plant claims to discharge no more than 1000 gallons of wastewater per hour, on the average, into a neighboring lake. An environmental action group decides to monitor the plant, in case this limit is being exceeded. Doing so is expensive, and only a small sample is possible. A random sample of four hours is selected over a period of a week. The observations are below. Assume the population is normally distributed.

(c) Using StatCrunch, show that the P-value is less than 0.05, so there is enough evidence to reject the null hypothesis at the 0.05 significance level.
P-value =   (3 decimal places)

(d) Will this test be valid?
a.Yes, because the population has a normal distribution.
b.Yes, the Central Limit Theorem can be used.
c.No, np and n(1-p) are not both greater than 15.
d.Yes, np and n(1-p) are both greater than 15.

Solution

Sol)

a) p value < 0.05 hence we reject the null hypothesis. hence can conclude that p value is lessthan 0.05

b) Yes, the Central Limit Theorem can be used.