MATH225 Week 2 Assignment Stem and Leaf plots (July 2019)

MATH 225 Statistical Reasoning for the Health Sciences

Week 2 Assignment Stem and Leaf plots

Question A set of data is summarized by the stem and leaf plot below.

Stem1234Leaf000011223445899990123667788890000001345567999923335567777889

Which of the following statements are true? Select all correct answers.

The value 18 appears 0 times in the data set.

The value 39 appears 4 times in the data set.

The value 21 appears 2 times in the data set.

The value 37 appears 0 times in the data set.

The value 42 appears 1 time in the data set.

The value 22 appears 1 time in the data set.

Question The ages of United States’ presidents inaugurated in the 20th century are summarized by the stem and leaf plot below.

Stem Leaf

4 236

5 111245566

6 01249

Which of the following statements are true? Choose all answers that apply.

There are 5 presidents in the data set whose age at inauguration was greater than or equal to 40 and less than or equal to 49.

There are 4 presidents in the data set whose age at inauguration was greater than or equal to 30 and less than or equal to 39.

There are 9 presidents in the data set whose age at inauguration was greater than or equal to 50 and less than or equal to 59.

There are 5 presidents in the data set whose age at inauguration was greater than or equal to 60 and less than or equal to 69.

There are 14 presidents in the data set whose age at inauguration was greater than or equal to 50 and less than or equal to 59.

Question Which data set is represented by this stem-and-leaf plot?

Stem Leaf

0 245

1 556667

2 0023488

3 1123333

2,4,5,15,16,17,20,22,23,24,28,31,31,32,33

2,4,5,15,15,16,16,17,20,20,22,23,24,28,31,31,32,33,33

2,4,5,15,15,16,16,16,17,20,20,22,23,24,28,28,31,31,32,33,33,33,33

12,14,15,15,15,16,16,16,17,20,20,22,23,24,28,28,31,31,32,33,33,33,33

Stem-and-Leaf Plots

Stem-and-Leaf Plots

A statistical graph is a tool that helps you see the shape of a distribution of a sample or a population. A graph is a more effective way of presenting data because we can see the clusters, outliers, etc.

One simple graph is the stem-and-leaf plot. It is a good choice when the data sets are small. To create a stem-and-leaf plot, each data value will be separated into a “stem” and a “leaf” using its digits. The “leaf” consists of a final significant digit. The stem contains the remaining digits in front of the “leaf”. For example:

• The number 23 has a stem of 2 and a leaf of 3.

• The number 432 has a stem of 43 and a leaf of 2.

• Likewise, the number 5432 has a stem of 543 and a leaf of 2.

When drawing the stem-and-leaf plot, make sure the data is ordered either in ascending or descending order. The stems are written in a vertical line from smallest to largest. Draw a vertical line to the right of the stems. Then write the leaves in increasing order next to their corresponding stem.

Data Set: 10,11,12,12,12,14,14,16,20,22,23,25,25,31,32,33,36,36,39

Stem-and-Leaf Plot:

Stem Leaf

1 01222446

2 02355

3 123669

Question

A set of data is summarized by the stem and leaf plot below.

Stem12Leaf01234778899913356777

There are $$___ values in the data set which are greater than or equal to 20 and less than or equal to 29. There are $$___ values in the data set which are greater than or equal to 10 and less than or equal to 19.

Question A set of data is summarized by the stem and leaf plot below.

Stem1234Leaf1356671123348900002367788811122334567777

There are $$___ values in the data set which are greater than or equal to 20 and less than or equal to 29. There are $$___ values in the data set which are greater than or equal to 10 and less than or equal to 19. There are $$__ values in the data set which are greater than or equal to 40 and less than or equal to 49.