Respuesta :
Answer:
12
Step-by-step explanation:
The missing number can be calculated by using the formula:
mean = (sum of data)÷(number of data points)
15 = [tex]\frac{18+16+x+9+12+23}{6}[/tex]
90 = 18+16+x+9+12+23
x=90-18-16-9-12-23
x=12
To check, just take the mean while including the found value for x:
mean = [tex]\frac{18+16+12+9+12+23}{6}[/tex] = [tex]\frac{90}{6}[/tex] = 15