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Author Question: The D statistic in item analysis is a measure of a) item difficulty b) item discrimination c) ... (Read 95 times) |
Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.
Fungal nail infections account for up to 30% of all skin infections. They affect 5% of the general population—mostly people over the age of 70.
It is widely believed that giving a daily oral dose of aspirin to heart attack patients improves their chances of survival because the aspirin blocks the formation of new blood clots.
Nearly 31 million adults in America have a total cholesterol level that is more than 240 mg per dL.
About 3% of all pregnant women will give birth to twins, which is an increase in rate of nearly 60% since the early 1980s.