GRE Math 2

Chapter 17: Problem Solving Word problems occur in several general mathematics categories: ·        Algebra ·        Arithmetic ·        Number properties ·        Geometry ·        Probability ·        Statistics These may have any of the three answer choice possibilities: ·        Numerical entry (single box = whole number or decimal value; one box above another = fraction) – use “Transfer Display” button on calculator to enter a numerical answer from your calculator, and use the hyphen “-“ for negative numbers ·        Single answer multiple choice (circles/ovals) ·        Select all that apply (boxes) – may have only one answer, may have more than one answer   Kaplan Method 1. Analyze ...

More from Ch. 13: Frequency distributions – describe how often certain data values occur in sets and show these in tables, histograms, charts, and graphs, usually as percentages (but also as fractions or decimals).   Relative frequency – each frequency divided by the total number of data points; relative frequency distribution, aka probability distribution, shows this frequency in decimal form instead of percentage. Note that the total of relative frequencies is 100%, or 1 if using fractions or decimals.   Normal distribution – also known as the bell curve – here the mean will equal the median and mode and data are symmetrically distributed. ·        Standard deviation determines how spread out the curve is ·        The mean indicates how far from the axis (usually (0, 0) or origin on the coordinate graph) the center of the curve lies   Visual representations of data most frequently come in bar ...

Chapter 13: Math Foundations – Statistics Review Strictly speaking, probability is a subset of statistics which measures the likelihood of events based on ratios. Statistics more broadly construed involves taking a sample from a population and deriving claims about the population based on the sample. More narrowly, we measure the central tendency (averages) and dispersion (spread) of the data in that sample.   Central Tendency (Averages) Mean – what we usually call an average, aka arithmetic mean Weighted mean – when we calculate the average by percentages of the whole, e.g. Median – the middle number Mode – the most frequent value(s) Each has a different use, and errors will come from misuse or misunderstanding.     Dispersion (Spread) Range – the distance (difference) between the least and the greatest terms Variance – the average of the squares of differences between each data point and the mean Standard deviation – the square root of the va...

Chapter 14: Math Foundations – Counting Methods & Probability Review Counting Methods: Probability The formulas from our memorization sheet are simplified to facilitate space; the ones in the notes here are a bit more detailed. For example, P(A) = frequency/outcomes; or in other words, the probability of any event A is frequency of the desired result over all possible outcomes. This is the Classical Probability Formula: (Kaplan has this as number of desired outcomes over number of possible outcomes, but the meaning is the same) Or P(A) = f ¸ n 1 is the value of absolute certainty, 0 is the value of absolute nonoccurrence. Thus, virtually all probabilities are fractions (or decimals). For example, a fifty percent chance of rain is a ½ probability, a 0.5 probability, or a 50% probability, i.e., fifty chances in one hundred. The higher the probability, the more likely the event will occur; and the lower the probability, ...