3. According to the theory of genetics a certain cross of guinea pigs will result in red, black and white off-springs in the ratio of 8:4:4. Find the probability that among 6 such off- springs 4 will be red, 1 black and 1 white. 4. A forester plants 5 seedlings selected at random from a bag containing 5 Douglas-fir and 6 hemlock seedlings. What is the probability that 2 firs and 3 hemlocks were planted? 5. The trees in a cutting block have an average diameter of 35 cm, have a standard deviation of 6 cm and are normally distributed. For appraisal purposes we need to know: 1. What proportion of trees is less than 25 cm in diameter (for pulp mill use)? 2. What proportion of trees is greater than or equal to 25 cm and less than or equal to 40 cm (for sawmill use)? 3. What proportion of trees is greater than 40 cm (for plywood use)? Assume that the trees can be measured to the nearest 0.1 cm