A statistician records every serve that a tennis player hits during the US Open Tennis Championship. The mean serve speed was 100 miles per hour (mph), and the standard deviation of the serve speed was 15 mph. If there is no information about the shape of the data, what percentage of the player's serve speeds are less than 70 mph? O Approximately 2.5% At most 11% At least 89% At most 25% At most 12.5%