math stat. ch.3
which letter represents the median?
Letter B represents the median because roughly half of the values in the distribution are to the left of B and roughly half of the values in the distribution are to the right of B.
True or False: Chebyshev's inequality applies to all distributions regardless of shape, but the empirical rule holds only for distributions that are bell shaped.
True, Chebyshev's inequality is less precise than the empirical rule, but will work for any distribution, while the empirical rule only works for bell-shaped distributions. Recall that Chebyshev's inequality gives the minimum percent of the observations that lie within k standard deviations of the mean, while the empirical rule gives an approximation of the exact percent of the observations that lie within k standard deviations.
For a distribution that is skewed left, the left whisker is ......... the right whisker
longer than
For a distribution that is skewed left, which of the following is true?
mean (less than) < median
which letter represents the mode?
represents the mode because it is at the peak of the distribution
For a distribution that is symmetric, the left whisker is ....... as the right whisker
the same length as
Scores of an IQ test have a bell-shaped distribution with a mean of 100100 and a standard deviation of 1616. Use the empirical rule to determine the following. (a) What percentage of people has an IQ score between 8484 and 116116? (b) What percentage of people has an IQ score less than 8484 or greater than 116116? (c) What percentage of people has an IQ score greater than 116116?
a) = 68% b)= c)= · Approximately 68% of the data will lie within 1 standard deviation of the mean. · Approximately 95% of the data will lie within 2 standard deviations of the mean. · Approximately 99.7% of the data will lie within 3 standard deviations of the mean