Answer:
5.9
Step-by-step explanation:
The mean means arithmetic average (some people just say average here).
The average of 4 numbers is the sum of those 4 numbers divided by the number of numbers which is 4 in this case.
So we have this formula:
[tex]\frac{3.8+4.2+5.3+x}{4}=4.8[/tex]
Multiply both sides by 4:
[tex]3.8+4.2+5.3+x=4(4.8)[/tex]
Simplify:
[tex]13.3+x=19.2[/tex]
Subtract 13.3 on both sides:
[tex]x=19.2-13.3[/tex]
Simplify:
[tex]x=5.9[/tex]
