Question

A Chip Company claims that there is 32 oz in every bag of chips with a specified population standard deviation of 1.5. A sample of 40 bags where weighted with an sample mean of 31.4. A consumer feels that this less than what the company claims.

Estimate the p-value, give accurate to four decimals; that is, 0.12345 or 12.345%, should be given as 0.1235.

Answer 1

solution.  

The null and alternative hypothesis is ,

H₀ :   = 32

H_a : < 32

Test statistic = z

= ( - ) / / n

= (31.4-32) / 1.5 / 40

=-2.53

P(z <-2.53   ) = 0.0057 using z table

P-value = 0.0057