1 Prop Z Test

Suppose the P-value for a hypothesis test is 0.0304. Using a = 0.05, what is the appropriate conclusion?

• a) Reject the null hypothesis

• b) Reject the alternative hypothesis

• c) Fail to reject the null hypothesis

• d) Fail to reject the alternative hypothesis

What is the only option for the null hypothesis? 

• H₀ = k
• H₀ > k
• H₀ < k
• H₀ ≠ k

The weight of the average 6th grade student's backpack (with books in it) is 18.4 lbs. The principal of the school thinks that the backpack does not weight 18.4 lbs. What is the null and alternate hypothesis? 

• H₀ = 18.4
  H_a = 18.4
• H₀ = 18.4
  H_a > 18.4
• H₀ = 18.4
  H_a < 18.4
• H₀ = 18.4
  H_a ≠ 18.4

Identify the correct null hypothesis:

Is the proportion of babies born male different from 50%? In a sample of 200 babies, 96 were male. Test the claim using a level of significance of 1%.

• H₀: p = 0.50

• H₀: µ = 100

• H₀: p = 0.48

• H₀: µ = 96

Lumber companies dry freshly cut wood in kilns before selling it. A certain percentage of boards develop cracks on their ends during drying. The current drying procedure is known to produce cracks in 16% of boards. The drying supervisor wants to try a new method that she believes will result in a proportion of cracked boards that is less than 16%.

Write the appropriate hypotheses.

• Ho: p = 0.16

  Ha: p = 0.16

• Ho: p = 0.16

  Ha: p =/= 0.16

• Ho: p = 0.16

  Ha: p > 0.16

• Ho: p = 0.16

  Ha: p < 0.16

• Since our p-value of 0.027 is >undefined , we fail to reject the null hypothesis. We do not have convincing evidence that the new method is better. 

Last year, a pineapple company in Hawaii grew pineapples that weighed an average of 31 ounces. The company installed a new irrigation system hoping that this year’s crop of pineapples would be larger than 31 ounces.

Write appropriate hypotheses.

• Ho: u = 31 ounces

  Ha: u > 31 ounces

• Ho: u = 31 ounces

  Ha: u < 31 ounces

• Ho: u = 31 ounces

  Ha: u =/= 31 ounces

• Ho: u = 31 ounces

  Ha: u = 31 ounces

• Since our p-value of 0.1317 is >undefined , we fail to reject the null hypothesis. We do not have convincing evidence that the pineapples are larger. 

Suppose the P-value for a hypothesis test is 0.0304. Using a = 0.05, what is the appropriate conclusion?

• a) Reject the null hypothesis

• b) Reject the alternative hypothesis

• c) Fail to reject the null hypothesis

• d) Fail to reject the alternative hypothesis

How small is a small p-value? All year we have defined small as any probability that is less than _________.

• 1%

• 2.5%

• 5%

• 10%