单选题 If X has a normal distribution with μ=100 and σ=5, then there is approximately a 90% probability that:
  • A. P(90.2<X<109.8).
  • B. P(87.1<X<112.9).
  • C. P(91.8<X<108.3).
【正确答案】 C
【答案解析】65 (5)=91.75 to 108.25 or P(91.75<X<108.25).