Answer Happy

1. The heights of a certain population of corn plants follow a normal distribution with mean 140 cm and standard deviation 20 cm. What is the probability that: (a) a single plant randomly selected has height above 150 cm? (b) that a single plant randomly selected has height between 135 and 150 cm? (c) that 10 plants randomly selected has mean height of between 135 and 150 cm? (d) 20 plants randomly selected has mean height between 135 and 150 cm? (e) 30 plants randomly selected has mean height between 135 and 150 cm? 2. In a certain population, systolic blood pressure (X) follows a normal distribution with a mean of 100 and standard deviation of 10. Calculate (a) P(X<115). (b) P(x - 1001<5). (c) P(X - 100 > 5). (d) P(X|<105), n = 20 (e) P(X - 100> 5), n = 20. 3. Calculate the following probabilities, where I ~ tm-1 and 2 ~ N(0.1). (a) PT > 2.5), n = 25 (b) PT> -3.1). n = 30 (c) PT < -2.6). n = 40 (d) P(2.1<T<5.7), n = 20 (e) P(Z < -2.1) (f) P(Z > 1.28) (g) P(-2.1<<6.8)