91Ó°ÊÓ

In a relative frequency distribution, what should the relative frequencies add up to?

True or False: When plotting an ogive, the plotted points have \(x\) -coordinates that are equal to the upper limits of each class.

What does it mean if a distribution is said to be "skewed left"?

True or False: There is not one particular frequency distribution that is correct, but there are frequency distributions that are less desirable than others.

True or False: Stem-and-leaf plots are particularly useful for large sets of data.

For each variable presented, state whether you would expect a histogram of the data to be bell-shaped, uniform, skewed left, or skewed right. Justify your reasoning. (a) Annual household incomes in the United States (b) Scores on a standardized exam such as the SAT (c) Number of people living in a household (d) Ages of patients diagnosed with Alzheimer's disease

For each variable presented, state whether you would expect a histogram of the data to be bell-shaped, uniform, skewed left, or skewed right. Justify your reasoning. (a) Number of alcoholic drinks consumed per week (b) Ages of students in a public school district (c) Ages of hearing-aid patients (d) Heights of full-grown men

Determine the original set of data. $$ \begin{aligned} &\begin{array}{l|l} 1 & 014 \\ 2 & 14479 \\ 3 & 3555778 \\ 4 & 001266899 \\ 5 & 3358 \\ 6 & 12 \end{array}\\\ &\text { Legend: } 1 \mid 0 \text { represents } 10 \end{aligned} $$

Federal Debt The following data represent the percentage of total federal debt held by the public as a percentage of gross domestic product (GDP). The GDP of a country is the total value of all goods and services produced within the country in a given year. It can be thought of as the total income of the country for the year. Construct a time-series plot and comment on any trends. $$ \begin{array}{lc|cc} \text { Year } & \text { Debt as \% GDP } & \text { Year } & \text { Debt as \% GDP } \\ \hline 1996 & 63.97 & 2006 & 60.99 \\ \hline 1997 & 62.37 & 2007 & 61.81 \\ \hline 1998 & 60.27 & 2008 & 67.84 \\ \hline 1999 & 57.99 & 2009 & 82.37 \\ \hline 2000 & 54.70 & 2010 & 90.44 \\ \hline 2001 & 54.30 & 2011 & 95.05 \\ \hline 2002 & 56.45 & 2012 & 98.81 \\ \hline 2003 & 58.72 & 2013 & 99.54 \\ \hline 2004 & 59.91 & 2014 & 102.84 \\ \hline 2005 & 60.37 & & \\ \hline \end{array} $$

The cumulative relative frequency for the last class must always be 1. Why?