24 Questions
What is the number of outcomes when a fair coin is tossed?
2 outcomes
In a positively skewed distribution, which of the following relationships is true for the mean, median, and mode?
The mean is greater than the median and mode
If the mean is 25 and the standard deviation is 5, what is the coefficient of variation?
20%
In a positively skewed distribution, what is the value of m3?
Positive
What type of measurement scale is used when data is labeled to identify an attribute of an element?
Nominal
What is the equation of a simple linear regression line?
Yˆ = 5 - 2X
What is the measure of data dispersion that is based on the deviations of individual data points from the mean?
Variance
What is the correlation coefficient that measures the strength and direction of the linear relationship between two variables?
-1 to 1
What is the type of average that is defined as the reciprocal of the arithmetic mean of the reciprocals of the values?
Harmonic mean
What type of average is used to find the average speed of a car that is running at different rates?
Harmonic mean
What is the probability of drawing a jack card from a standard deck of 52 playing cards?
4/52
What is the value of the correlation coefficient if all the values fall on the same straight line with a positive slope?
r = +1
What type of curve has a longer tail to the right?
Positively skewed
Which one of the following is not a measure of central tendency?
Range
What is the purpose of class intervals in descriptive statistics?
To organize data into groups
If the data points fall on a straight line with a positive slope, what is the value of the correlation coefficient?
r = +1
What is the condition for the correlation coefficient to be zero in a regression line Y = a + bX?
Slope b = 0
What is the purpose of tally marks in descriptive statistics?
To count the frequency of each value
What is the probability of getting at least one head when two coins are tossed?
3/4
Which measure does not divide a set of observations into equal parts?
Standard deviations
In the model Y = mX + a, what is Y also known as?
Predicted (dependent) variable
According to the empirical rule, approximately what percentage of measurements will fall within which interval?
95% fall within X ± 2S
What is the correlation coefficient used to measure?
The strength of a linear relationship
In a regression line, what does the slope (b) represent?
The change in Y for a one-unit change in X
Study Notes
Descriptive Statistics
- In a positively skewed curve, the mean is greater than the median.
The variance is a measure of dispersion.
Probability
- When a coin is tossed, there are 2 outcomes (heads or tails).
- The probability of getting at least one head when two coins are tossed is 3/4.
Regression Analysis
- In a regression equation, Y is also known as the dependent variable or predicted variable.
- In a regression line Y = a + bX, the value of the correlation coefficient will be zero if the slope b = 0.
Measurement Scales
- When data is labeled to identify an attribute of an element, the measurement scale is nominal.
- Ordinal scale is used when data is ranked or labeled to identify an attribute of an element, but the differences between the scale values are not equal.
Data Distribution
- In a positively skewed distribution, m3 (the third moment) is positive.
- According to the empirical rule, approximately 95% of the measurements will fall within the interval X ± 2S.
Averages
- The harmonic mean is the average defined as the reciprocal of the arithmetic mean of the reciprocals of the values.
- The weighted mean is used to find the average speed/hr when the rate of a car changes during different intervals.
Probability and Statistics
- The probability of drawing a particular card from a deck of 52 playing cards is 1/52.
- Quartiles divide a set of observations into four equal parts.
- The range, interquartile range, and variance are measures of dispersion.
Test your knowledge of statistical measures, including mean, median, mode, and variance, in positively skewed curves.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
