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The term "skyscraper" is reserved for buildings at least 10 floors in height. Research over the last 40 years has shown that the number of floors of newly-built skyscrapers has a mean of 50 floors and a standard deviation of 10 floors. If nothing is known about the shape of the number-of-floors distribution, what percentage of the newly-built skyscrapers is less than 30 floors? O Approximately 2.5% O At most 25% O At most 11% At most 12.5%