Question

1. A sample of 21 boxes of “Chocolate Crème Covered Coconut Crispy Chip Co-Co Cookies” showed a mean of 23.5 ounces and a standard deviation of 1.1 ounces. Check the hypothesis claim that boxes have the proper weight of 24 ounces. Use α= 0.10 significance; for the original claim H0: μ = 24 and H1: μ < 24.

   1. t (statistic) =_ _

   2. t (critical) = __________

Reject or fail to reject H0? _______

Answer 1

Solution :

= 24

=23.5

S =1.1

n = 21

This is the left tailed test .

The null and alternative hypothesis is ,

H₀ :    = 24

H_a : < 24

Test statistic = t

= ( - ) / S / n

= (23.5-24) / 1.1 / 21

= −2.083

Test statistic = t =  −2.083

The t critical value = −1.325

P-value =0.0251

= 0.1

P-value <

0.0251 < 0.1

Reject the null hypothesis .

There is sufficient evidence to claim that the population mean μ is less than 24, at the 0.1 significance level.