Earthquake aftershock magnitudes. Seismologists use the term “aftershock” to describe the...

Earthquake aftershock magnitudes. Seismologists use the term “aftershock” to describe the smaller earthquakes that follow a main earthquake. Following the Northridge earthquake of January 17, 1994, the Los Angeles area experienced 2,929 aftershocks in a three-week period. The magnitudes (measured on the Richter scale) of these aftershocks were recorded by the U.S. Geological Survey and are saved in the EARTHQUAKE file. A MINITAB relative frequency histogram for these magnitudes follows.

a. Estimate the percentage of the 2,929 aftershocks measuring between 1.5 and 2.5 on the Richter scale.

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b. Estimate the percentage of the 2,929 aftershocks measuring greater than 3.0 on the Richter scale.

MINITAB Output