Homework 7 (20 points)
STAT 110
Name(s) ______SOLUTION________
Due: Tuesday, April 30th by 4pm
1. It is believed that a person’s height should be the same as their wingspan. This was
demonstrated in the famous sketch by Leonardo Da Vinci called the Vitruvian Man.
Using the data set Vitruvian_Man.jmp found on the course website, answer the following
research question. Make sure to provide a detailed sketch or paste your JMP output below.
Research Question – Is there evidence that a person’s wingspan and height are not the
same?
Difference = Height – Wingspan
H0: µd = 0
Ha: µd ≠ 0
Condition: npairs = 40 ≥ 30√
Test Statistic = t =
-0.81 - 0 -0.81
=
= -2.77
1.84
0.29
40
p-value = 0.0085
Evidence that a person’s wingspan and height are not the same.
1
2. The Ohio Environmental Protection Agency used the Index of Biotic Integrity (IBI) to measure
the biological condition, or “health” of an aquatic region. The IBI is the sum of metrics that
measure the presence, abundance, and health of fish in the region. Higher values of the IBI
correspond to healthier fish populations. Researchers collected IBI measurements for sited
located in difference Ohio River basins. (Journal of Agriculture, Biology, and Environmental
Sciences, June 2005) The data collected from the Muskingum and Hocking river basins obtained
is in the file IBI.jmp found on the course website. Using the data, answer the research question
given below. Make sure to provide a detailed sketch or paste your JMP output below.
Research Question – Is there evidence the mean IBI value for the Muskingum River basin
is bigger than the mean IBI value for the Hocking River basin?
H0: µmuskingum ≤ µhocking
Ha: µmuskingum > µhocking
Condition: nmusingum = 53 ≥ 30 and nhocking = 51 ≥ 30√
Test statistic = t =
0.10607
= 1.04
0.10221
p-value = 0.1509
No evidence that the mean IBI values differ for the two river basins.
2