Question

The accompanying specific gravity values for various wood types used in construction appeared in the article “Bolted Connection Design Values Based on European Yield Model” (J. of Structural Engr., 1993: 2169–2186):

.31	.35	.36	.36	.37	.38	.40	.40	.40
.41	.41	.42	.42	.42	.42	.42	.43	.44
.45	.46	.46	.47	.48	.48	.48	.51	.54
.54	.55	.58	.62	.66	.66	.67	.68	.75

Construct a stem-and-leaf display using repeated stems, and comment on any interesting features of the display.

Short answer

The stem and leaf display for the provided scenario is,

Unit: 3L|1=0.31 and 3R|5=0.35.

Step-by-step solution

Given information

The gravity values for various wood types used in construction is provided as,

.31	.35	.36	.36	.37	.38	.40	.40	.40
.41	.41	.42	.42	.42	.42	.42	.43	.44
.45	.46	.46	.47	.48	.48	.48	.51	.54
.54	.55	.58	.62	.66	.66	.67	.68	.75

Construct a stem and leaf diagram and comment

a.

A stem-and-leaf display providesa visual representation of the dataset.

The steps to construct a stem-and-leaf display are as follows,

1) Select the leading digit for the stem and trailing digits for the leaves.

2) Represent the stem digits vertically and similarly the trailing digits corresponding to the stem digits.

3) Mention the units for the display.

The stem and leaf display for the provided scenario is,

Unit: 3L|1=0.31 and 3R|5=0.35.

From the above display, the features are,

1)It can be observed that a good representative strength value is 0.45.

2) The display appears to be right or positively skewed and not symmetric.

3) The range of the data is 0.44 (0.75-0.31).

4)There is a reasonably large amount of variation in the data.

5)A possible outlier can be observed as 0.75.