Q. 26 - Elementary Statistics

Question

26. Latent Fingerprints. Firearms, live ammunition, and spent cartridge casings are often submitted to crime laboratories to be processed for latent fingerprints. B. Maldonado explored the chances of successfully recovering fingerprints in the article, "Study on Developing Latent Fingerprints on Firearm Evidence" (Journal of Forensic identification, Vol. 62, Issue 5, pp. 425-429). The following table provides a frequency distribution for the type of evidence submitted to crime laboratories over a 2-year period at the Denver Police Department.

Evidence	Frequency
Firearm	289
Magazine	161
Live Cartridge	2727
Spent Cartridge Casing	259

a. Obtain a relative-frequency distribution.
b. Draw a pie chart.
c. Construct a bar chart.
d. Interpret your results.

Step-by-Step Solution

Answer

(a) Obtained a relative-frequency distribution as:

(b) A pie chart is obtained as:

(c) Construct a bar chart as:

(d) Most of evidence comes from live cartridge.

Part (a) Step 1: Given information

To obtain a relative-frequency distribution with given data.

Evidence	Frequency
Firearm	289
Magazine	161
Live Cartridge	2727
Spent Cartridge Casing	259

Part (a) Step 2: Explanation

In a dot plot, a dot is placed above the corresponding number on the number line for each set of data. Obtained a relative-frequency distribution as:

As a result, a relative-frequency distribution is obtained.

Part (b) Step 1: Given information

To draw a pie chart with given data.

Evidence	Frequency
Firearm	289
Magazine	161
Live Cartridge	2727
Spent Cartridge Casing	259

Part (b) Step 2: Explanation

The number of data values that fall into a class is known as frequency. Draw a pie chart as follows:

As a result, the pie chart is obtained.

Part (c) Step 1: Given information

To construct a bar chart with given data.

Evidence	Frequency
Firearm	289
Magazine	161
Live Cartridge	2727
Spent Cartridge Casing	259

Part (c) Step 2: Explanation

The number of data values that fall into a class is known as frequency.
Construct a bar chart as follows:

Part (d) Step 1: Given information

To interpret the results with given data.

Evidence	Frequency
Firearm	289
Magazine	161
Live Cartridge	2727
Spent Cartridge Casing	259

Part (d) Step 2: Explanation

Since the group corresponds to the greatest slice in the pie chart and the highest bar in the bar chart, the most of evidence comes from live cartridge.