Chapter 1-9 Flashcards
An outlier is a data value that…
…is not consistent with the bulk of the data
Which statistics is not resistant to an outlier in the data?
Mean
Which one of these statistics would be affected by an outlier?
Standard Deviation
Which of these statistics is unaffected (not affected) by outliers? A. Mean B. SD C. Interquartile Range D. Range
C. Interquartile range
…
…
True or False: Outliers cause complications in all statistical analysis
False: outliers do affect such statistics such as means and standard deviation but there are appropriate measures of location and spread
True or false: since outliers cause complications in statistical analyses, they should be discarded before computing summaries such as the mean and the standard deviation
False: they should never be discarded without justification
What is a reasonable action if an outlier was a mistake made in measuring the object?
The value should be corrected if possible or discarded if not possible to correct it
What is a reasonable action if an outlier is the value for the only young subject in a sample where all the other values were older subjects?
The value should be discarded and the results summarised and reported for the older subjects only
Tallies and cross-tabulations are used to summarise which of these variable types? A. Quantitative. B. Mathematical C. Continuous D. Categorical
D. Categorical
Which of these variables is a categorical variable?
A. Number of ear pierces a person has
B. Height of a person
C. Weight of a person
D Opinion about legalisation of marijuana
D.
Which of the following variables is not categorical? A. Age of a person B. Gender of a person C. Choice of test item: true of false D. Martial status of a person
A. Age
Which of the following is not a term used for quantitative variable? A. Measurement variable B. Numerical variable C. Continuous Variable D. Categorical variable
D. Categorical variable
A variable that is not the main concern of the study but may be partially responsible for the observed results is known as…
… the cofounding variable
_______ of only a few thousands, or few hundreds, can give reasonable accurate information about a population of many millions
A representative sample
All of the following are categorical variables except?
A. Gender of a student
B. Colour of a car entering the parking low
C. Number of flowers on an azalea plant
D. The state in which a person lives
C.
Which of the following is not a continuous variable?
A. A persons body temp
B. Number of claims received by an insurance company during one day
C. Weight of two dozen shrimp
D. Height in inches of freshman at a university
B.
An experiment was conducted to compare the mean lengths of time required for the body to absorb two drugs ( A and B ). Ten people were randomly selected and assigned to receive one of the drugs. The length of time In minutes for the drug to reach a specified level In the blood was recorded. What is the explanatory variable in tis study?
The type fo drug
What is the percent of data which lies between the minimum and the upper quartile?
75%
Which of the following would indicate that a dataset is not bell shaped?
A. The range is equally to 6 SD
B. The range is larger than the interquartile range
C. The mean is much smaller than the median
D. There are no outliers
C.
Exam scores in % range from 0 to 100. Suppose an exam was difficult and most of the students scored low with only a few students scoring high. Which would best describe the shape of the distribution?
A. Right - Skewed
B. Left - skewed
Right-skewed
If a diagram moves from high (left) to low (right). What direction is it skewed.
Skewed to the right
When the results of an experiment can be applied to real-world conditions, that experiment is said to have... A. Factorial Validity B. Criterion Validity C. Ecological Validity D. Content Validity
C
A frequency distribution in which high scores are most frequent (i.e bars on the graph are highest on the right hand side) is said to be... A. Negatively skewed B. Leptokurtic C. Positively skewed D. Platykurtic
A