Question

The mean weight per student in a group of 7 students is 55 kg. The individual weights of 6
of them (in kg) are 52, 54, 55, 53, 56 and 54. Find the weight of the seventh student.

Answer 1

The mean weight per student in a group of 7 students is 55kg.

Weight of 6 students (in kg) = 52,54,55,53,56 and 54.

Let weight of 7^th student = x kg

       

     ∴  Mean = `"Sum of all weights"/" Total students"`

          ⇒ 55 =  `(52 +54 +55 +53 +56 +54 +x)/7`
  

          ⇒ 385 = 324 + x

          ⇒  x = 385 - 324

          ⇒  x = 61 kg

 

∴ Weight of 7^th student = 61kg