We are given that:
\(m = -0.5n + 10\)
Here, m = corrected value
n = observed value
Before we proceed, we need to understand the effect of addition and multiplication on both mean and SD.
For mean: If there is a set {a,b,c} with mean x; and we add 10 to each of the values in the set, then the set becomes {a+10,b+10,c+10} and the corresponding new mean becomes x+10
This same principle is applicable for "mean" when we multiply the set values with another value
For SD: First thing to note is that SD can never be negative, since this tells us the spread of the data
Secondly, addition and subtraction to the set values has no effect on SD. Only multiplication and division change the SD.
For e.g., if we have a set {a,b,c} with SD = S; and we multiply all the values in the set with 10, then the set becomes {10a, 10b, 10c} and the new SD = 10S
Using the above, we can say that for the corrected mean:
we have, \(7.3(-0.5)+10 = 6.35\)
For the corrected SD, we have:
\(2.9(0.5) = 1.45\)
Answer:
Corrected mean: 6.35
Corrected SD: 1.45