If the mean of a normal frequency distribution of 1000 items is 25 and its standard deviation is 2.5, then its maximum ordinate is
- A. 1000 e^-25 / $\sqrt{2pi}$
- B. 1000 / $\sqrt{2pi}$
- C. 1000 e^-2.5 / $\sqrt{2pi}$
- D. 400 / $\sqrt{2pi}$
Answer: D. 400 / $\sqrt{2pi}$
Explanation: Max ordinate is at mean. Value = N / (sigma * $\sqrt{2pi}$). 1000 / (2.5 * $\sqrt{2pi}$) = 400 / $\sqrt{2pi}$.