Head movement evaluations are important because disabled
individuals may be able to operate communications aids using head
motion. A paper reported the accompanying data on neck rotation (in
degrees) for 14 subjects both in the clockwise direction (CL) and
in the counterclockwise direction (CO). For purposes of this
exercise, you can assume that the 14 subjects are representative of
the population of adult Americans.
Subject: 1 2 3 4 5 6 7 8 9 10 11 12 13 14
CL: 57.3 35.7 54.5 56.8 51.1 70.8 77.3 51.6 54.7 63.6 59.2 59.2
55.8 38.2
CO: 44.7 52.1 60.2 52.7 47.2 65.6 71.4 48.8 53.1 66.3 59.8 47.5
64.5 34.6
Based on these data, is it reasonable to conclude that mean neck
rotation is greater in the clockwise direction than in the
counterclockwise direction? Carry out a hypothesis test using a
significance level of 0.01. (Use a statistical computer package to
calculate the P-value. Use μCL − μCO. Round your test statistic to
two decimal places and your P-value to three decimal places.)
t=
df =
P-value =
