Answer:
Step-by-step explanation:
Express Courier Service has found that the delivery time for packages is normally distributed. So we use
z = (x - mean)/standard deviation
mean = 13
standard deviation = 2
x = time of delivery in hours
a) P(0 lesser than/equal to 18)
z = (18-13)/2 =5/2 = 2.5
Using the normal distribution table, the value is 0.9938
b) to be 95% sure, let the time be t
From the table, the equivalent of z that is 0.95 = 1.645
So 1.645 = (t-13)/2
t-13 = 3.29
t = 3.29+13= 16.29 hours
Answer:
Amaia walked 28 meters
Step-by-step explanation:
So first we know that the side x+3 is equal to the side 3x+1
subtract 1 and x from both sides to get x=1
then we plug in the 1 to the equation x+9 and we know that side equals 10, meaning the parallel side is also 10.
plug in 1 to one of the original equations to get 4
4+4+10+10=28
Luckily, all of the denominators are factors of 100.
rainy: 12/100
sunny: 44/100
partly cloudy: 30/100
cloudy: 10/100
happy learning!
-mathgurl
Answer:
A
Step-by-step explanation:
Consider the equation for the circumference of a circle, 2πr. Notice that this can also be written as 2rπ.
Recall that the diameter of a circle is equal to twice the radius, or
d = 2r
And make a substitution into the original equation, giving us the circumference c = πd. We know the circumference is 5.2mm; plugging in, we get
5.2 = πd.
Note: π is NOT a variable, it represents a number. Therefore, we can solve the equation for the diameter d = c / π, or
d = 5.2 / π.
I'll let you crunch the number :D
I hope this helps!