How many times do 15 minutes fit into one hour? 4 times: 4*15=60 mins.
So that means that 4 times per hour 10 flights appear, and in total 4*10=40 planes arrive over one hour!
Answer:
g = 21/4
Decimal form:
g = 5.25
Mixed Number:
5 1/4
Answer:

Step-by-step explanation:
Given: 76,45,64,80,92
Required: Determine the standard deviation
We start by calculating the mean

Where x-> 76,45,64,80,92 and n = 5



Subtract Mean (71.4) from each of the given data

Determine the absolute value of the above result

Square Individual Result

Calculate the mean of the above result to give the variance


Hence, Variance = 255.298
Standard Deviation is calculated by 



Note that there's a strict order here -> 2 close friends, then 1 non-close friend.
So, picking in order:
probability of picking the first close friend: 4/10
probability of picking the second close friend: 3/9
probability of picking the first non-close friend: 6/8
So, we get 4/10 * 3/9 * 6/8 = 1/10.
I’m not 100% sure this is correct, because I’ve never done these before, but try 12, this is the answer I got from a reliable app that I usually use