Chapter 3.1, Problem 27E

To determine

Possible scatterplot to illustrate the situation.

Explanation of Solution

Given information:

Correlation,

  $r=0.98$

Rob’s scores are always lower than Marc’s.

When r is positive, positive linear correlation exists.

When r is negative, negative linear correlation exists.

For weak correlation,

  $0<\left|r\right|<0.5$

For moderate correlation,

  $0.5<\left|r\right|<0.8$

For strong correlation,

  $0.8<\left|r\right|<1$

Note that

The association between scores of Rob and Marc is strong and positive association.

Since the data involves same 10 essays for both the teachers.

Moreover,

The points should lie perfectly in straight line that slopes upwards.

However,

Make sure that Rob’s scores are always lower than Marc’s.

Assume that

Scores were in percentage.

Thus,

The highest possible score is 100%.