business statistics
1.
Dogs have been domesticated for about 14,000 years. In that time, have they been able to develop an
understanding of human gestures such as pointing or glancing. How about similar nonhuman cues?
Researchers Udell, Giglio, and Wynne tested a small number of dogs in order to answer these questions. To
test this, the researchers positioned the dogs about 2.5 meters from the experimenter. On each side of the
experimenter were two cups. The experimenter would perform some sort of gesture (pointing, bowing,
looking) toward one of the cups or there would be some other nonhuman gesture (a mechanical arm
pointing, a doll pointing, or a stuffed animal looking) toward one of the cups. The researchers would then
see whether the dog would go to the cup that was indicated. There were six dogs tested, but we will look at
one of the dogs in two of his sets of trials. This dog, a four-year-old mixed breed, was named Harley. Each
trial involved one gesture and one pair of cups, with a total of 10 trials in a set. Harley was tested 10 times
and 9 of those times he chose the correct cup.
Is there evidence to support the argument that Harley can understand human cues? Why or why not?
2.
People spend a lot of money on bottled water. But do they really prefer bottled water to ordinary tap water?
Researchers at Longwood University (Lunsford and Dowling Fink, 2010) investigated this question by
presenting people who came to a booth at a local festival with four cups of water. Three cups contained
different brands of bottled water, and one cup was filled with tap water. Each subject (person) was asked
which of the four cups of water they most preferred. Researchers kept track of how many people chose tap
water in order to see whether tap water was chosen significantly less often than would be expected by
random chance. The researchers found that 3 of 27 subjects selected tap water. Determine whether there is
evidence of the researchers’ claim or not.
3.
A study in Psychonomic Bulletin and Review (Lea, Thomas, Lamkin, and Bell, 2007) presented evidence
that “people use facial prototypes when they encounter different names.” Participants were given two faces
and asked to identify which one was Tim and which one was Bob. The researchers wrote that their
participants “overwhelmingly agreed” on which face belonged to Tim and which face belonged to Bob but
did not provide the exact results of their study. Suppose we reproduced this study and saw that out of a
class of 25, 18 correctly guessed that the face on the left was Tim. Do we have evidence to support the
researchers’ claim?
4.
A study conducted by Hill and Barton (Nature, 2005) investigated whether Olympic athletes in certain
uniform colors have an advantage over their competitors (They were just interested in whether one color
would win more often than the other). They noticed that competitors in the combat sports of boxing, tae
kwon do, Greco-Roman wrestling, and freestyle wrestling are randomly assigned red or blue uniforms. For
each match in the 2004 Olympics, they recorded the uniform color of the winner. Researchers Hill and
Barton used data collected on the results of 457 matches and found that the competitor wearing red won
248 times, whereas the competitor wearing blue won 209 times. Carry out a simulation study to assess
whether or not the observed data provide evidence in support of the research conjecture.
5.
When asked to call the outcome of a coin toss, are people equally likely to choose heads or tails? In a
sample done at the gym, 54 of 83 participants picked heads; is there enough evidence to support the claim
that people are equally likely to choose heads or tails?
