Evaluating Data & Making Conjectures Examples

This stem and leaf plot represents the predicted high temperatures for New York City in the next 10 days.

5|7 represents a predicted temperature of 57 degrees Fahrenheit. Using the stem and leaf plot, determine which statement is accurate.

a) It is going to be very, very hot during the next 10 days.

b) It is going to freeze in the next 10 days.

c) The temperature will remain mostly in the 60’s in the next 10 days.

d) There is one day during which the temperature is likely to be 30 degrees colder than the other days.

The answer is c. Most of the leaves on this stem and leaf plot are on the 60’s stem, so the temperature will remain mostly in the 60’s for the next 10 days.

This histogram represents the scores from the last geometry test. They are graphed with a bin width of 7. Which of the following questions about test performance can be answered based on this graph?

a) What were the two most common ranges of scores on the test and why?

b) Why did the majority of the class fail the test?

c) Why did most of the class get above 90 on the test?

d) How did 3 people get 100 on the test?

The correct answer is a. The two highest columns represent the two most common ranges of scores on the test. It is clear the majority of the class did not fail, nor did they get above 90, and no one got 100.

This box and whisker plot represents the amount of money Mateo earned the past 18 weeks while working at his dad's shop.

What is a reasonable explanation for the outlier and what could it tell us about Mateo’s earnings?

a) Mateo earned the same amount of money each day that he worked.

b) Mateo’s dad pays him more money just once in every 18 weeks.

c) Mateo worked longer than average during one of the 18 weeks so he earned more money.

d) Mateo could have worked 20 weeks instead of 18.

The correct answer is c. One data point is significantly higher than the other data points. This data point represents one week during which Mateo made significantly more money than the other weeks, and the most likely reason for this is that Mateo worked more hours this week.