A truck company wants on-time delivery for 98% of the parts they order from a metal manufacturing plant. They have been ordering from Hudson Manufacturing but will switch to a new, cheaper manufacturer (Steel-R-Us) unless there is evidence that this new manufacturer cannot meet the 98% on-time goal. As a test the truck company purchases a random sample of metal parts from Steel-R-Us, and then determines if these parts were delivered on-time. Which hypotheses should they test? A) H0: p 0.98 B) H0: p 0.98 HA: p = 0.98 C) H0: p = 0.98 HA: p 0.98

Question

A truck company wants on-time delivery for 98% of the parts they order from a metal manufacturing plant. They have been ordering from Hudson Manufacturing but will switch to a new, cheaper manufacturer (Steel-R-Us) unless there is evidence that this new manufacturer cannot meet the 98% on-time goal. As a test the truck company purchases a random sample of metal parts from Steel-R-Us, and then determines if these parts were delivered on-time. Which hypotheses should they test? A) H0: p < 0.98 HA: p > 0.98 B) H0: p > 0.98 HA: p = 0.98 C) H0: p = 0.98 HA: p < 0.98 D) H0: p = 0.98 HA: p ≠ 0.98 E) H0: p = 0.98 HA: p > 0.98

Quizplus · Accepted Answer

The truck company wants on-time delivery for 98% of the parts they order from a metal manufacturing plant. Hence, the null hypothesis (H0) should be that the proportion of on-time delivery is equal to 0.98 (p=0.98), and the alternative hypothesis (HA) should be that the proportion of on-time delivery is less than 0.98 (p<0.98), as the truck company would switch to a new, cheaper manufacturer only if there is evidence that the new manufacturer cannot meet the 98% on-time goal. Therefore, the correct choice is C: H0: p = 0.98 HA: p < 0.98.

A Truck Company Wants On-Time Delivery for 98% of the Parts