A sociologist studying the difference in ages between husbands and wives obtained a random sample of 55 married couples. The mea
n of the husbands’ ages was 38.5 years with standard deviation 12.6 years. The mean of the wives’ ages was 36.9 years with standard deviation 12.4 years. The sociologist calculated the difference between the ages for each couple. The mean difference was 1.6 years with standard deviation 2.1 years. A matched-pairs hypothesis test will be performed to investigate whether the difference is significant.
If CAB represents a line and has arrows indicating its endpoints, then CAB is identified as a straight line, which also corresponds to a straight angle measuring 180°.