In this question a vital information has been provided. This information can be used for determining the answer to the question that is asked. It is given that 120% of a certain number is 360 pound. The 100% value of the number needs to be determined.
Let us assume the number to be = x
Then
120x/100 = 360
12x/10 = 360
12x = 360 * 10
12x = 3600
x = 3600/12
= 300
Now we can say that the 100% of the number or the actual number is 300 pounds. I hope the problem is clear to you and you can understand the trick involved in the question.
This problem is in Khan Academy
In this graph the instantaneous velocity=decline.
You just have to do this:
And the answer is letter (A)
My answer Is The 4th Statement because a positive number is on the other side of the number line as the negative number and if it were just negative 5 and positive 5 it would be correct. I’m just trying the best I can to help you .
Say we add 5 to each element. We sum them up and divide by the number of elements (compute mean). Well we added 5n to that total sum and are dividing by n. So if the mean was 10 before, now it’s 15. (We had 10 datapoints added too 100, but we added 50, dividing by 10 we get 15).
Now every single data point is just as close to the mean as it was before. The mean shifted with 5, but so did the datapoints. Remember, variance is the sum of squared errors divided by n, or n-1 for sample. Well, the sum of squared errors did not change. So our estimate of variance remains the same as well as our estimate of standard deviation.
This is without assuming normality. (ie through the equation of mean and standard deviation themselves). In general expected values shift with constants, and variances remain stable.
