The mean is calculated by adding up all of the given numbers and dividing by the number of numbers.
Lets, for ease of understanding, say that the first three number were 64...
Mean=(64+64+64)/3=192/3=64
Now, lets solve for the mean where 'x' is the unknown fourth number and 128 is the mean. (since, the answer said that when the fourth number was added the mean, 64, was doubled '64*2=128')
128=(64+64+64+x)/4
128=(192+x)/4
Multiply both sides by 4
512=192+x
subtract 192 from both sides
320=x
The missing number is 320..
Now lets double check our work.
Mean=(64+64+64+320)/4=512/4=128
Answer=320
Answer:
A
Step-by-step explanation:
X for number of true/false questions and y for number of multiple choice questions:
3x+11y=100
x+y=20
Solve the system and the answer is 5 multiple choice questions.
Answer: $90
Step-by-step explanation:
To find 60% of 150, you can simply use this equation, 60 X 150 divided by 100. That will leave you with 90, which is the amount he paid for the shoes. :)
Answer:
I am pretty sure its A.week 18
Step-by-step explanation:
just add 5 untill you get 122
