Question

Suppose it is known that heights of 8 year old Unrisunas trees are approximately normally distributed with a mean of 75.5" and standard deviation or = 8.3". [5 pts) What is the probability that a randomly selected tree is taller than 74”? [2 pts] If we sample 14 of those trees, what is the standard deviation of the distribution of sample means for this sample? [4 pts] If you sample 14 trees, what is the probability that the mean height of the 14 trees is greater than 80”?

Answer 1

christmass Х 8-3 -height of tree (normal) M - 755 8-M= 3-75.5 in pln>74) - prz>-0.18) = 10.5914 2=74-75.5 8.3 =-0.18 (og nal24 = 8.3 = 2.2183 then Viu mean liz=(75.5 and Standard deviation at Plim >80) = Plz>2.03). (60212) 41. 50-7505 = 2.03 2.2183 Mr = 1=795.5 100212 (1) 22 2.2183