Answer:
x = 51
Step-by-step explanation:
If the mean = 11.5, then that means all numbers added together divided by four = 11.5. Let's write this algebraically:
[tex]\frac{12.5+(-10)+(-7.5)+x}{4}=11.5[/tex]
Now, let's solve for x:
[tex]12.5-10-7.5+x=11.5(4)[/tex]
[tex]-5+x=46[/tex]
[tex]x=51[/tex]
I hope this helps!
