Answer:the fourth number is =97
Step-by-step explanation:
Mean = total number of the given numbers( x1 +x2+ x3....) / numbers given
Let the fourth number be x
given that the mean of 4 numbers = 88 and only 3 numbers are given
such that
Mean = total number of the given numbers( x1 +x2+ x3....) / numbers given becomes
88= (80 +90 + 85 + x ) / 4
88 x 4 =80 +90 + 85 + x
352=255+x
x= 352-255
x=97
