Earthquakes in the United States. Assume for a recent 41- year period in the United States, there were 268 earthquakes measured at 6.0 or higher on the Richter scale. Round to 4 decimals. 1) Find the probability that in a given year, there is at least one earthquake in the United States that measures 6.0 or higher?_______________ 3) Is it likely or unlikely to have an earthquake a year? ____________