Chapter 1.2, Problem 41E

(a)

To determine

To sketch:a dotplot for a distribution that is skewed to the left.

Answer to Problem 41E

  

Explanation of Solution

Calculation:

Students marks in Statistical subject is given below:

Marks in Statistics	Frequency
$12$	$1$
$13$	$1$
$15$	$1$
$16$	$1$
$17$	$2$
$17$	$1$
$18$	$2$
$18$	$1$
$19$	$3$
$19$	$2$
$19$	$1$
$20$	$4$
$20$	$3$
$20$	$2$
$20$	$1$
$21$	$10$
$21$	$9$
$21$	$8$
$21$	$7$
$21$	$6$
$21$	$5$
$21$	$4$
$21$	$3$
$21$	$2$
$21$	$1$
$22$	$7$
$22$	$6$
$22$	$5$
$22$	$4$
$22$	$3$
$22$	$2$
$22$	$1$
$23$	$3$
$23$	$2$
$23$	$1$

The dot plot based in the data above is skewed toward left:

  

Conclusion:

Therefore, the dotplot for a distribution is plotted.

(b)

To determine

To explain:why thedistribution of dates is skewed to the left.

Answer to Problem 41E

The distribution is skewed towards left because most of the coins were of recent manufacture year.

Explanation of Solution

Calculation:

Here we can conduct an experiment of dates on coins by recording the years marked on each coin from pockets of two persons.

Year	Frequency
$1991$	$1$
$1991$	$2$
$2001$	$1$
$2001$	$2$
$2001$	$3$
$2002$	$1$
$2002$	$2$
$2003$	$1$
$2005$	$1$
$2005$	$2$
$2005$	$3$
$2005$	$4$
$2008$	$1$
$2008$	$2$
$2010$	$1$
$2011$	$1$
$2011$	$2$
$2011$	$3$
$2011$	$4$
$2011$	$5$

The dotplot is given below:

  

The distribution is skewed towards left because most of the coins were of recent manufacture year.

Conclusion:

Therefore, the distribution is skewed towards left because most of the coins were of recent manufacture year.