Chapter 21: Introduction to Statistical Analysis

Chapter 21: Introduction to Statistical Analysis

 

Complete Chapter Questions With Answers

 

Sample Questions Are Posted Below

 

MULTIPLE CHOICE

 

1. A researcher who has conducted experimental research finds that in his 145-person hospital study the patients who are ambulated on the evening of abdominal surgery are less likely than the control group to develop postoperative pneumonia. What does the researcher infer?

a.	The control group resembled the experimental group in all important characteristics.
b.	Early ambulation and pneumonia are strongly related.
c.	Evening-of-surgery ambulation will prevent some cases of postoperative pneumonia in abdominal surgery patients.
d.	Careful support of the abdomen is important for postoperative ambulation in patients who have had abdominal surgery.

 

 

ANS:  C

Statisticians use the term inference or infer in somewhat the same way that a researcher uses the term generalize. Inference requires the use of inductive reasoning. One infers from a specific case to a general truth, from a part to the whole, from the concrete to the abstract, from the known to the unknown. When using inferential reasoning, one can never prove things; one can never be certain. However, the rules that have been established with regard to statistical procedures so as to increase the probability that inferences are accurate. Inferences are made cautiously and with great care. Researchers use inferences to infer from the sample in their study to the larger population.

 

DIF:    Cognitive Level: Analysis                REF:   Page 537

 

2. What is this particular distribution called?

a.	Bimodal
b.	Normal
c.	Camelesque
d.	Negatively skewed

 

 

ANS:  A

Another characteristic of distributions is their modality. Most curves found in practice are unimodal, which means that they have one mode and frequencies progressively decline as they move away from the mode. Symmetrical distributions are usually unimodal. However, curves can also be bimodal or multimodal. accurately reflect the shape of the population from which the sample was taken.

 

DIF:    Cognitive Level: Application           REF:   Page 540

 

3. A researcher reports that the heights of men aged 53 living in Rapid City, South Dakota, are between 5’7” and 6’0” and that the confidence interval is calculated at the p <.05 level. What does this mean?

a.	If the heights of men in Rapid City, South Dakota, do not fall within the confidence interval at least 5% of the time, a type I error has occurred.
b.	If a 53-year-old man in Rapid City, South Dakota, is measured, there is a 95% chance that his height will fall in the 5’7” through 6’0” interval.
c.	Ninety-five percent of the 53-year-old men living in Rapid City, South Dakota, are between 5’7” and 6’0”.
d.	The heights of the men in the sample were all between 5’7” and 6’0”, and the sample was representative of 95% of the men in town.

 

 

ANS:  B

When the probability of including the value of the parameter within the interval estimate is known, this is referred to as a confidence interval. Calculating a confidence interval involves the use of two formulas to identify the upper and lower ends of the interval. A confidence interval is actually an estimate.

 

DIF:    Cognitive Level: Synthesis              REF:   Page 541

 

4. There are four data sets:

A:   1, 1, 1, 1, 1, 10, 10, 10, 10

B:   2, 2, 2, 2, 4, 8, 8, 8, 9

C:   3, 4, 4, 5, 5, 5, 6, 6, 7

D:   1, 2, 3, 4, 5, 6, 7, 8, 9

What is the mean of the four individual data sets?

a.	5, 5, 5, 5
b.	1, 4, 5, 5
c.	1, 2, 5, 5
d.	5

 

 

ANS:  A

The measures of central tendency are descriptive statistics. The statistics that represent “measures of central tendency” are the mean, median, and mode. All of these statistics are representations or descriptions of the center or middle of a frequency distribution. The mean is the arithmetic average of all of a variable’s values. The median is the exact middle value (or the average of the middle two values if there is an even number of observations). The mode is the most commonly occurring value in a data set. In a normal curve, the mean, median, and mode will be equal or approximately equal

 

DIF:    Cognitive Level: Analysis                REF:   Page 538

 

5. There are four data sets:

A:   1, 1, 1, 1, 1, 10, 10, 10, 10

B:   2, 2, 2, 2, 4, 8, 8, 8, 9

C:   3, 4, 4, 5, 5, 5, 6, 6, 7

D:   1, 2, 3, 4, 5, 6, 7, 8, 9

What is the median of the four individual data sets?

a.	5, 5, 5, 5
b.	1, 4, 5, 5
c.	1, 2, 5, 5
d.	5

 

 

ANS:  B

The measures of central tendency are descriptive statistics. The statistics that represent “measures of central tendency” are the mean, median, and mode. All of these statistics are representations or descriptions of the center or middle of a frequency distribution. The mean is the arithmetic average of all of a variable’s values. The median is the exact middle value (or the average of the middle two values if there is an even number of observations). The mode is the most commonly occurring value in a data set. In a normal curve, the mean, median, and mode will be equal or approximately equal.

 

DIF:    Cognitive Level: Analysis                REF:   Page 538