BrownMath.com → Statistics → Sum15 ME58 → Sleep Lab
Updated 25 May 2015

# Sleep Lab (Due on 10 Jun)

Summary: You will gather some data about people’s sleeping habits and summarize the data.

## Data Collection

Choose a systematic sample (k = 3) of 24 adults aged 18 or older, and ask them how many hours they slept last night (to the nearest hour), and their position for going to sleep (back, left side, right side, stomach, or unsure). Add yourself as the 25th data point. Record the answers using the form at the end of the lab, or separate paper laid out the same way.

## Directions for This Lab

• On separate paper, show your work and then your answer for the first question, your work and then your answer for the second question, and so on. You must show your work including tallies for full credit. I recommend you use your calculator for calculations, but you may use Excel instead if you wish.
• Check the numbers you enter in your calculator! It’s pretty bad if your answers don’t match your data. When you can, use TI calculator commands instead of formulas. Show calculator commands, not keystrokes.
• Do all the graphs on graph paper or in Excel. Need graph paper? Here’s a sheet you can download and print (9 KB PDF), adapted from Kevin MacLeod’s Plain Graph Paper PDF Generator.
• Use at least half the page for each graph. Know when an axis must start at zero and when it should not.
• Do a professional job: Write neatly and legibly, remove any “decorative fringe” from the paper, and so forth. I recommend pencil and eraser because correcting mistakes in ink is a bear. Word processing is also acceptable.
• Hand in your data sheet. I can’t accept the lab without the full set of raw data.
• Don’t hand in the questions.
• Staple all pages neatly before you come to class, because loose sheets and insecure fasteners cost a 10% penalty. You don’t need a report cover.

## Data Analysis

Question 1 (points: 3):  State the date, time, and place where you took your sample. How did you choose your first participant, and how did you choose the others?

The next two questions apply to your data for sleeping position.

Question 2 (points: 2):  What is the type of the data? (Give the most specific answer.)

Question 3 (points: 5):  Out of bar graph, pie chart, histogram, and stem-and-leaf, construct the most appropriate graph for this data set. Include any necessary labels or scaling.

The rest of the questions apply to your data for hours slept.

Question 4 (points: 2):  What is the type of the data? (Give the most specific answer.)

Question 5 (points: 5):  Out of bar graph, pie chart, histogram, and stem-and-leaf, construct the most appropriate graph for this data set. Include any necessary labels or scaling.

Question 6 (points: 3):  Compute the mean and SD of this data set. Report them with their symbols, showing the unrounded numbers and then rounding to one decimal place.
Example:  = 2.059126028 → 2.1

Question 7 (points: 2):  Compute and report the five-number summary.

Question 8 (points: 4): On graph paper, draw a modified boxplot. Include any outliers, and show and label the axis. (No need for formulas: use your TI to help you.)

Question 9 (points: 2):  What’s your raw score? (How many hours did you sleep?) What’s your percentile rank — in other words, what percent of the sample slept less than you or the same amount? (Remember that you are part of the sample.)

Question 10 (points: 2):  Find your own z-score in this data set, rounded to two decimals. Beware The Big No-no!

Sleep Data Collected from 25 Persons
Hours slept
(nearest hour)
Position
(BA, LS, RS, ST, U)
Hours slept
(nearest hour)
Position
(BA, LS, RS, ST, U)

YOU

Updates and new info: http://BrownMath.com/stat15b/