# How would adding 50 points to each score affect the mean?

Question
How would adding 50 points to each score affect the mean?

2020-11-12
The mean would increase by 50 points.

### Relevant Questions

A population of N =16 scores has a mean of p = 20, After one score is removed from the population, the new mean is found to be $$\displaystyleμ={19}$$. What is the value of ine score that was removed? (Hint: Compare the val- ues for X before and after the score was removed.)
In one study, the correlation between the educational level of husbands and wives in a certain town was about 0.50, both averaged 12 years of schooling completed, with an SD of 3 years.
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This is how I answered it. P($$\displaystyle{X}_{{1}}$$ and $$\displaystyle{Y}_{{2}}$$) $$\displaystyle={P}{\left({X}_{{1}}\right)}\times{P}{\left({Y}_{{1}}{\mid}{X}_{{1}}\right)}={.75}\times{.40}={0.3}.$$
What I don't understand is how do you get the $$\displaystyle{P}{\left({Y}_{{1}}{\mid}{X}_{{1}}\right)}$$? I am totally new to Statistices and I need to understand each part of the process in order to get the whole concept. Can anyone help me to understand why the P and X exist and what they represent?
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