Question

The standard deviation for the scores $1,2,3,4,5,6$ and $7$ is $2.$ Then, the standard deviation of $13,24,35,46,57,68$ and $79$ is

• A. $2$
• B. $4$
• C. $22$
• D. $11$
• E. $44$

Answer 1

The correct option is C

$22$

Explanation for the correct option

Let $x=1,2,3,4,5,6,7$and $y=13,24,35,46,57,68,79$

$y_i=11x_i+2$(for $i=1,2,....7$)

$\therefore$Standard Deviation of $y_i=11\times$Standard Deviation of $x_i$

$\therefore$Standard Deviation of $y_i=11\times 2=22$

Hence the correct option is option (c).