2.2 histograms
Histogram
A histogram is a bar graph in which the horizontal scale represents classes of data values and the vertical scale represents frequencies. The heights of the bars correspond to the frequency values, and the bars are drawn adjacent to each other (without gaps). shows shape of distribution shows location of center shows the spread of data identifies outliers use class midpoints to separate each bar
Fill in the blank. The heights of the bars of a histogram correspond to _______ values
Frequency
The histogram to the right represents the weights (in pounds) of members of a certain high-school math team. How many team members are included in the histogram?
In the histogram above, the y-axis is ticked for every 1-person increase in frequency, so the number of team members in each class is given by the height of the bar in ticks.
The population of ages at inauguration of all U.S. Presidents who had professions in the military is 62, 46, 68, 64, 57. Why does it not make sense to construct a histogram for this data set?
With a data set that is so small, the true nature of the distribution cannot be seen with a histogram.
Fill in the blank. A(n) _______ distribution has a "bell" shape.
normal
A _______ histogram has the same shape and horizontal scale as a histogram, but the vertical scale is marked with relative frequencies instead of actual frequencies.
relative frequency histogram A relative frequency histogram has the same shape and horizontal scale as a histogram, but the vertical scale is marked with relative frequencies (as percentages or proportions) instead of actual frequencies.
Fill in the blank. A histogram aids in analyzing the _______ of the data.
shape of the distribution A histogram is a visual tool used to represent and analyze data. It is basically a graphic version of a frequency distribution, and it can show the center, variation, and the shape of the distribution of the data.
The bars in a histogram _______.
touch A histogram is a graph consisting of bars of equal width drawn adjacent to each other (without gaps). Therefore, the bars touch
