Question

Which of these stem-and-leaf plots has the highest mean?

• A.

  Steam	Leaf
  $3$	$24$
  $4$	$358$
  $5$	$148$
  $6$	$479$

  
  Key $3|2=32$
• B.

  Steam	Leaf
  $4$	$236$
  $5$	$147$
  $6$	$369$
  $7$	$024$

  
  Key $4|2=42$
• C.

  Steam	Leaf
  $3$	$79$
  $4$	$3678$
  $5$	$112679$
  $6$	$345$

  
  Key $3|7=37$
• D.

  Steam	Leaf
  $3$	$111$
  $4$	$469$
  $5$	$018$
  $6$	$159$

  
  Key $3|1=31$

Answer 1

The correct option is B

Steam	Leaf
$4$	$236$
$5$	$147$
$6$	$369$
$7$	$024$

Key $4|2=42$
Option A:
The values from the stem-and-leaf plot are:
$37,39,43,46,47,48,51,51,52,56,57,59,63,64,65$
Mean $=\frac{37+39+43+46+47+48+51+51+52+56+57+59+63+64+65}{15}$
Mean $=\frac{778}{15}$
Mean $=51.87$

Option B:
The values from the stem-and-leaf plot are:
$32,34,43,45,48,51,54,58,64,67,69$
Mean $=\frac{32+34+43+45+48+51+54+58+64+67+69}{11}$
Mean $=\frac{565}{11}$
Mean $=51.36$

Option C:
The values from the stem-and-leaf plot are:
$31,31,32,44,46,49,50,51,58,61,65,69$
Mean $=\frac{31+31+32+44+46+49+50+51+58+61+65+69}{12}$
Mean $=48.92$

Option D:
The values from the stem-and-leaf plot are:
$42,43,46,51,54,57,63,66,69,70,72,74$
Mean $=\frac{42+43+46+51+54+57+63+66+69+70+72+74}{12}$
Mean $=58.92$

So, comparing the 4 means, we can conclude that option D has the highest mean.