Question

If the mean of 3,7,11 and x is 9, what is the value of x?​

Answer 1

Answer:

Mean = Sum of observations / Total no of observations

Total number of observations = 4

• 9 = (3+7+11+x) / 4
• 9x4 = 3+7+11+x
• 36 = 21+x
• 36-21 = x
• 15 = x

Therefore value of x is 15

Answer 2

Answer:

x = 15

Step-by-step explanation:

Mean = sum of observations/total number of observations

9 = (3 + 7 + 11 + x)/4

9 = (21 + x)/4

9 × 4 = 21 + x

36 = 21 + x

x = 36 - 21

x = 15

Hope it helps u☺