Answer:
6
Step-by-step explanation:
The mean is calculated as
mean = [tex]\frac{sum}{count}[/tex]
let x be the fourth number, then
[tex]\frac{9+14+15+x}{4}[/tex] = 11 ( multiply both sides by 4 )
38 + x = 44 ( subtract 38 from both sides )
x = 6
The number on the fourth card is 6
