Lumber companies dry freshly cut boards in kilns before selling them. As a result of the drying process, a certain percentage of the boards crack. The current drying procedure is known to produce cracks in 16% of the boards. The drying supervisor wants to test a new method to determine if fewer boards will crack.
What is the null hypothesis (H0)? Be sure to define the parameter of interest.
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What is the alternate hypothesis (Ha)?
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Is the alternate hypothesis one or two sided?
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Lumber companies dry freshly cut boards in kilns before selling them. As a result of the drying process, a
certain percentage of the boards crack. The current drying procedure is known to produce cracks in 16% of the boards. The drying supervisor wants to test a new method to determine if fewer boards will crack.
To investigate, he selected an SRS of 50 boards, dried them using the new method, and found 5 that cracked ( pˆ = 5 / 50 = 0.10) . To determine if these data provide convincing evidence that less than 16% of the boards will crack when using the new method, 100 trials of a simulation were conducted. Each dot in the graph below shows the proportion of boards that cracked in a random sample of 50 boards, assuming that each board has a 16% chance of cracking
Use the simulation results to estimate the P-value of the test. Intepret the value.
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Based on the p-value above, what would you conclude at a significance level of 10%?
