Answer:
A task time of 177.125s qualify individuals for such training.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by

After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X. Subtracting 1 by the pvalue, we This p-value is the probability that the value of the measure is greater than X.
In this problem, we have that:
A distribution that can be approximated by a normal distribution with a mean value of 145 sec and a standard deviation of 25 sec, so
.
The fastest 10% are to be given advanced training. What task times qualify individuals for such training?
This is the value of X when Z has a pvalue of 0.90.
Z has a pvalue of 0.90 when it is between 1.28 and 1.29. So we want to find X when
.
So




A task time of 177.125s qualify individuals for such training.
Answer:
the probability that all tomatoes are sold is 0.919 (91.9%)
Step-by-step explanation:
since the random variable X= number of tomatoes that are demanded, is normally distributed we can make the standard random variable Z such that:
Z=(X-μ)/σ = (83 - 125)/30 = -1.4
where μ= expected value of X= mean of X (since X is normally distributed) , σ=standard deviation of X
then all tomatoes are sold if the demand surpasses 83 tomatos , therefore
P(X>83) = P(Z>-1.4) = 1- P(Z≤-1.4)
from tables of standard normal distribution →P(Z≤-1.4)=0.081 , therefore
P(X>83) = 1- P(Z≤-1.4) = 1 - 0.081 = 0.919 (91.9%)
thus the probability that all tomatoes are sold is 0.919 (91.9%)
Answer:
Picture
Step-by-step explanation:
I graphed them