Answer:
Step-by-step explanation:
if you need help let me know
Answer:
hey dude, The formula is (x-y)³=x³-3x²y+3xy²-y³.
Subtract thats how you get it
Answer:
And if we solve for a we got
And for this case the answer would be 35185 the lowest 1% for the salary
Step-by-step explanation:
Let X the random variable that represent the salary, and for this case we can assume that the distribution for X is given by:
Where
and
And we want to find a value a, such that we satisfy this condition:
(a)
(b)
We can use the z score again in order to find the value a.
As we can see on the figure attached the z value that satisfy the condition with 0.01 of the area on the left and 0.99 of the area on the right it's z=-2.33. On this case P(Z<-2.33)=0.01 and P(z>-2.33)=0.99
If we use condition (b) from previous we have this:
But we know which value of z satisfy the previous equation so then we can do this:
And if we solve for a we got
And for this case the answer would be 35185 the lowest 1% for the salary
Answer: 0.0228
Step-by-step explanation:
Given : The mean and the standard deviation of finish times (in minutes) for this event are respectively as :-

If the distribution of finish times is approximately bell-shaped and symmetric, then it must be normally distributed.
Let X be the random variable that represents the finish times for this event.
z score : 

Now, the probability of runners who finish in under 19 minutes by using standard normal distribution table :-

Hence, the approximate proportion of runners who finish in under 19 minutes = 0.0228