PSY/315
Ch. 1 Practice Problems
Name
12. Explain and give an example for each of the following types of variables: (a) equalinterval, (b) rank-order, (c) nominal, (d) ratio scale, (e) continuous.
a.)
Equal-interval: A variable wherein the figures represent essentially the
same quantity of what is being calculated.
Instance: The variation between 30 degrees Fahrenheit and 60 degrees
Fahrenheit is an equal-interval variable to the variation between 80
degrees Fahrenheit and 110 degrees Fahrenheit.
b.)
Rank-order: A number variable wherein the values mean ranks (also
known as ordinal variable).
Instance: The sequence in which individuals completed in a race (1st, 2nd,
3rd, etc.)
c.)
Nominal: A variable wherein the values are types instead of quantities.
Instance: One instance would be computing figures regarding people’s
faith. Some might be Catholic, Mormon, Jewish, etc. These variables take
the shape of types instead of quantities in the study.
d.)
Ratio scale: An equal-interval variable is calculated on a ratio scale when
it has got an absolute zero point, which implies that there's a total absence
of a variable.
Instance: An individual's age may be one instance of a ratio scale. An
individual that is 30 years old is two times as old as an individual who is 15
years old. No person can have an age of “0”.
e.)
Continuous: The theory is that, a continuous variable is a variable for
which usually there are enormous quantities of values in between any two
values.
Instance: Somebody's weight may be an instance of a continuous
variable. Usually people will state that they weigh 130 pounds, however
they may possibly weigh 130.8 pounds.
15. Following are the speeds of 40 cars clocked by radar on a particular road in a 35mph zone on a particular afternoon: 30, 36, 42, 36, 30, 52, 36, 34, 36, 33, 30, 32, 35,
32, 37, 34, 36, 31, 35, 20, 24, 46, 23, 31, 32, 45, 34, 37, 28, 40, 34, 38, 40, 52, 31, 33,
15, 27, 36, 40
Make (a) a frequency table and (b) a histogram. Then (c) describe the general shape of
the distribution.
a.)
Frequency Table
SPEED
FREQUENCY
PERCENTAGE
15-19
1
2.5
20-24
3
7.5
25-29
2
5
30-34
15
37.5
35-39
11
27.5
40-44
4
10
45-49
2
5
50-54
2
5
b.)
Histogram
c.)
The overall form of the distribution is unimodal since there are two pretty
equal high points (speeds of 29.5-34.5 and 34.5-39.5). It's also possible to
call the distribution roughly symmetrical since if we folded the graph in two
the two sides would almost appear the same.
19. Give an example of something having these distribution shapes: (a) bimodal, (b)
approximately rectangular, and (c) positively skewed. Do not use an example given in
this book or in class.
a.)
Bimodal: In case a class of pupils took an exam and the majority of pupils
obtained between 89.5-94.5% and the second biggest category of pupils
obtained between 84.5-89.5% with the remainder of the class scoring
inconsistently between 60% and 99% this will generate a bimodal
distribution since there will be two pretty equally high places without other
regularity all through.
b.)
Approximately rectangular: An illustration of a roughly rectangular
distribution pattern will be a classroom of 20 kindergarteners. In case 16 of
the kindergarteners were five years of age and four were six years of age
this will generate a roughly rectangular distribution.
c.)
Positively skewed: In case a study were carried out on a group of 50
freshman college pupils computing the quantity of hours which they spent
on homework on every day basis this may create a positively skewed
distribution. In case twenty pupils spent just -1 hours on homework each
day, fifteen pupils spent 1-2 hours each day, ten students spent 2-3 hours
each day, 3 spent 3-4 hours each day, and 2 spent 4-5 hours each day on
homework, the outcomes will be a positively skewed distribution pattern.
20. Find an example in a newspaper or magazine of a graph that misleads by failing to
use equal interval sizes or by exaggerating proportions.
The objective of this chart is to display the DOW downfall from the start of November
2008, indicating that the decline began with the election of President Obama. What the
chart does not display is the downfall which had began to occur before the presidential
election. In fact, DOW started to decline in May, 2008, however this chart does not
indicate that since it just exhibits the decline from November, 2008, that leads
individuals to believe that this drop is a result of President Obama being selected.
21. Nownes (2000) surveyed representatives of interest groups who were registered as
lobbyists of three U.S. state legislatures. One of the issues he studied was whether
interest groups are in competition with each other. Table 1–10 shows the results for one
such question. (a) Using this table as an example, explain the idea of a frequency table
to a person who has never had a course in statistics. (b) Explain the general meaning of
the pattern of results.
a.)
A frequency table is frequently utilized so as to make sense of the data
which has been gathered and to display any kind of signs which may be
present. Table 1-10 demonstrates that this specific group encounters
some rivalry most of the time (58%), and either no rivalry or a great deal of
rivalry quite proportionately (20%-22%). By utilizing a frequency table you
can observe the trend of rivalry which the group usually encounters. The
table assists make sense of the percentages and quantities which exist in
the data which was collected. Without the utilization of the frequency table
one may get perplexed between the percentages and the quantities in the
study, therefore this table is a superb visual method of splitting down the
data in order that it's simpler to understand.
b.)
The end result shapes from table 1-10 are split up to exhibit the frequency
that this specific team encounters rivalry from various other similar teams.
Every response is provided in both per cent and numerical pattern to
indicate the relationship between the two results. There were an overall
total of 591 teams which took part in this analysis. From the 591 groups,
118 of these posed no rivalry, and 118 is 20% of the total 591 teams
which took part in the analysis. Out from the 591 teams in the analysis,
342 teams presented some rivalry, that is 58% of the 591 teams. Finally,
131 teams presented a great deal of rivalry, that is 22% of the 591 teams
in the analysis.
22. Mouradian (2001) surveyed college students selected from a screening session to
include two groups: (a) “Perpetrators”—students who reported at least one violent act
(hitting, shoving, etc.) against their partner in their current or most recent relationship—
and (b) “Comparisons”—students who did not report any such uses of violence in any of
their last three relationships. At the actual testing session, the students first read a
description of an aggressive behavior such as, “Throw something at his or her partner”
or “Say something to upset his or her partner.” They then were asked to write “as many
examples of circumstances of situations as [they could] in which a person might engage
in behaviors or acts of this sort with or towards their significant other.” Table 1–11
shows the “Dominant Category of Explanation” (the category a participant used most)
for females and males, broken down by comparisons and perpetrators. (a) Using this
table as an example, explain the idea of a frequency table to a person who has never
had a course in statistics. (b) Explain the general meaning of the pattern of results.
a.)
This research has got the possibility to turn out to be pretty perplexing
because of the quantity of information and data being utilized finish the
research. The frequency table assists explain the information here by
sorting out the data in a very clear and brief way. The table is split up to
exhibit the frequency (quantity) and the per cent of occurrences which
every team (female and male) has experienced each one of the category
situations.
b.)
The trend of outcomes for this table display that most of the women
perpetrators show intimate hostility because of control causes whereas
men perpetrators show intimate hostility out of expressive aggression. The
table also demonstrates that the greatest percentage of intimate
aggression for both male and female comparisons was out of rejection of
perpetrator or action with the next to the highest being control causes.