Question

A city office in Florida claims that an industrial plant discharge greater than 1000 gallons of wastewater per hour in the neighboring lake. To test this claim seven random sample are taken which showed sample mean as 1500. Let the population standard deviation is known to be 421. What is the test value?

Answer 1

Solution :

this is the right tailed test .  

The null and alternative hypothesis is ,

H0 :   = 1000

Ha : > 1000

Test statistic = z

= ( - ) / / n

= (1500-1000) / 421 / 7

= 3.14