Answer:
The approximate probability that a randomly selected aspen tree in this park in 1975 would have a diameter less than 5.5 inches = 0.15866
Step-by-step explanation:
The complete question is presented in the attached image to this answer.
It is stated that the distribution of tree diameters is approximately normal, hence, this is a normal distribution problem with
Mean diameter = μ = 8 inches
Standard deviation = σ = 2.5 inches
The approximate probability that a randomly selected aspen tree in this park in 1975 would have a diameter less than 5.5 inches = P(x < 5.5)
To solve this, we first normalize or standardize 5.5 inches
The standardized score for 45mg/L is the value minus the mean then divided by the standard deviation.
z = (x - μ)/σ = (5.5 - 8)/2.5 = - 1.00
The required probability
P(x < 5.5) = P(z < -1.00)
We'll use data from the normal probability table for these probabilities
P(x < 5.5) = P(z < -1.00) = 0.15866
Hope this Helps!!!
