John's commute time to work during the week follows the normal probability distribution with a mean time of 26.7 minutes and a s
tandard deviation of 5.1 minutes. what is the probability that the commute time for a randomly selected day will be more than 30 minutes?
1 answer:
A suitable probability calculator will tell you that probabilty is about 25.9%.
_____
The normalcdf function on this calculator gives an area between a lower and upper limit. If the upper limit is more than about 8 standard deviations above the mean, the 10th decimal place is unaffected. Since the standard deviation here is about 5, we need to have an upper limit that is about 40 above the mean of about 30. We have chosen 80 as a nice round number and to give a little more margin.
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Answer:
y = 60
Step-by-step explanation:
<h3>Step 1: Make sense of the given</h3>"The ratio of y to x is 3"
This means that,
"The sum of y and x is 80"
This means,
If , then
.
We can plug this into the other equation by substitution:
This simplifies to:
Which we can solve out and get:.
We solved for x, but we need the value of y.
So, we go back to the equation we first derived: "".
And now we substitute the value of x, into this.
By solving this out, we get:
So, the value of y is 60.
Answer:
41.67
Step-by-step explanation:
Using the tangent on the stick with shadow:
tan(θ) =
Using the tangent on the building:
tan(θ) =
⇒ h = 25 · tan(θ)
= 25 ·
⇒ h = 41.66... ≈ 41.67