Name: __________________________________

AP Biology Summer Assignment 2020-2021 Wall High School

Part I: Introduction to Statistical Tests

In AP biology we frequently use the website bozemanscience.com to watch video lectures and

tutorials on important concepts throughout the school year. Paul Anderson, an AP biology

teacher in Bozeman, Montana, created the website to assist his own students in preparing for

the AP exam, and it quickly became a popular resource for all AP biology students and teachers

across the country. Over the summer, you are going to use this resource to learn a little bit

about the statistical tests that we will be using on our experimental data generated in the labs

that we perform throughout the coming school year. Some of these important tests include

standard deviation, standard error, and the chi-squared test. These statistical tests are

important because they allow us to determine the quality and reliability of the data that we

generate in our lab investigations. For each statistical test, you will watch a video tutorial,

answer a few questions, and complete a few practice problems. You must print out this

assignment and hand write your responses - a hard copy must be turned in on the first day of

school (if we are virtual you will need to scan your work and email it to me). This part of the

summer assignment will count as ½ of a MINOR ASSESSMENT GRADE and must be turned in

on the first day of school: Tuesday, September 8th. Late assignments will not be accepted;

you will receive a zero if it is not turned in on time. The other ½ of the MINOR ASSESSMENT

GRADE for this assignment will come from an in-class quiz on these statistical tests on

Thursday September 10th.

Part II: Statistics and Graphing in Google Sheets

For most of our labs, we will be using Google Sheets to perform the statistical tests you will

learn about in Part I and to graph our data. The purpose of this part of the summer assignment

is to familiarize you with this program so that you are comfortable using it before the school

year begins. You will need to collect some authentic data and enter it into Google Sheets to

complete this assignment. The instructions provided will walk you through it step-by-step and

you will submit this assignment by sharing the final product with me via Google once you have

finished. If you have trouble completing this assignment on your own there will be an extra

help session during the first week of school. YOU MUST do this assignment individually; you

cannot share data or spreadsheets with anyone else - if any students turn in identical Google

Sheets with identical data (or a copy of someone else’s) they will receive a zero on this

assignment. This part of the summer assignment will count as ONE MINOR ASSESSMENT

GRADE and must be shared with me via Google by 7:20 AM Friday, September 11th. There

will be an extra help session on Thursday, September 10th after school if you need help with

this assignment. If the assignment is not shared on time you will receive a zero.

Name: ____________________________________

Part I: Introduction to Statistical Tests – DUE on the first day of school (Tues. Sept. 8th)

Directions: Go to the website http://www.bozemanscience.com/statistics-graphing and under

“Unit 1: Statistics”, click on the “Statistics for Science” link and watch the video. Answer the

following questions as you watch, all responses to questions in Part I should be hand-written in

this packet and a hard copy must be turned in:

1. What is “statistics”?

2. What is “big data”? Describe one example.

3. What is a population? Describe one example.

a. What do the symbols N and n represent?

b. Which do we use more often in science – the entire population or the sample?

Explain why.

c. What is the mean? What symbol is used to represent the mean?

d. What is the median? What symbol is used to represent the median?

e. What is the range?

f. What equation is used to determine “degrees of freedom”? If you have 8

measurements or 8 trials in your experiment, what are your degrees of freedom?

Go back to “Unit 1: Statistics” and click on the “Standard Deviation” video:

http://www.bozemanscience.com/standard-deviation. Answer the following questions:

4. What does the normal distribution for a data set look like? Sketch and describe the

normal distribution in the space below:

5. What does standard deviation measure?

6. One standard deviation above and below includes ______% of individuals in the

population. Two standard deviations above and below the mean includes _____% of

individuals in the population. Three standard deviations above and below the mean

includes _____% of individuals in the population.

7. Standard deviation is “a measure of ____________________” in your data.

8. Write out the equation for standard deviation in the space below and explain what each

symbol in the equation represents:

9. Watch as he explains the example problem. Write out the solution to this example

problem as you watch and circle the final answer.

10. Pause the video and calculate the standard deviation by hand for the next data set (0, 2,

4, 5, 7). YOU MUST SHOW YOUR WORK in the space below and CIRCLE YOUR FINAL

ANSWER (round to the nearest hundredth):

11. Watch the spreadsheet shortcut in Excel. Check to make sure that your answer

matches!

12. After the video, complete these additional practice problems for standard deviation

using the following data table:

Table 1. Bacterial cell counts per milliliter in a control group (no antibiotic) and when

treated with two different antibiotics (ampicillin and tetracycline).

Time Control Ampicillin Tetracycline

Trial 1 29 21 11

Trial 2 45 24 19

Trial 3 31 23 36

Trial 4 53 19 17

Mean

Std. Dev.

Std. Error

a. First calculate the mean (average) for each data set and enter these values into

Table 1 above. You do not have to show your work for these calculations.

b. Calculate the standard deviation for the CONTROL data set and enter this value

into Table 1. YOU MUST SHOW YOUR WORK in the space below and CIRCLE

YOUR FINAL ANSWER (round to the nearest hundredth):

c. Calculate the standard deviation for the AMPICILLIN data and enter this value

into Table 1. YOU MUST SHOW YOUR WORK in the space below and CIRCLE

YOUR FINAL ANSWER (round to the nearest hundredth):

d. Calculate the standard deviation for the TETRACYCLINE data and enter this value

into Table 1. YOU MUST SHOW YOUR WORK in the space below and CIRCLE

YOUR FINAL ANSWER (round to the nearest hundredth):

Go back to “Unit 1: Statistics” and click on the “Standard Error” video

http://www.bozemanscience.com/standard-error. Answer the following questions:

13. What does standard error show you?

14. Write out the equation for standard error in the space below and explain what each

symbol in the equation represents:

15. Standard error is “a measure of ____________________” for your data.

16. Watch as he explains the example problem for data set 2. Write out the solution to this

example problem as you watch and circle the final answer.

17. Pause the video and calculate the standard error for data set 1. Show your work in the

space below and circle your final answer (round to the nearest hundredth):

18. After the video, complete these additional practice problems:

a. Calculate the standard error for the CONTROL data from Table 1 in #12. YOU

MUST SHOW YOUR WORK in the space below and CIRCLE YOUR FINAL ANSWER

(round to the nearest hundredth). Add this value to Table 1 in #12:

b. Calculate the standard error for the AMPICILLIN data from #12. YOU MUST

SHOW YOUR WORK in the space below and CIRCLE YOUR FINAL ANSWER (round

to the nearest hundredth). Add this value to Table 1 in #12:

c. Calculate the standard error for the TETRACYCLINE data from #12. YOU MUST

SHOW YOUR WORK in the space below and CIRCLE YOUR FINAL ANSWER (round

to the nearest hundredth). Add this value to Table 1 in #12:

d. Based on your calculations, which data set (control, ampicillin, tetracycline) is

the most consistent and probably the most reliable? Explain how you know.

Name: ____________________________________

Part II: Statistics and Graphing in Google Sheets - DUE Friday September 11th)

1. Log into Google using your school account and open up Google Sheets by clicking on the

apps icon on the upper right corner of the Google home screen:

2. In Google Sheets, create a data table with the following setup:

3. Also, at the top of the spreadsheet it will say “Untitled Document” in gray italics. Click in

this area and name the document using the following format: “Your last name AP

Biology Summer Assignment” The document will automatically save itself to your

Google Account. If you need to go back to your spreadsheet at any time you can log

into Google and open up Google Sheets and you will see your file. You can also access

your files through the Google Drive app.

4. Now you are going to need to collect some authentic data for your spreadsheet so that

we can practice doing some statistics and graphing in Google Sheets. Pick five different

plants from your yard or nearby park. You must find out the common name for each

plant that you choose (hydrangea, rhododendron, boxwood, pine tree, etc…). For each

of these plants, you are going to measure the length of five different leaves in

centimeters using a metric ruler (DO NOT use inches!). Your measurements should be

made to a tenth of a centimeter (example – 2.3 cm, 5.1 cm, etc…). You do not need to

remove the leaves from the plant, just make the measurement directly from the plant

and record your data on a piece of paper. Once you have made all of your

measurements, enter the data into your Google spreadsheet. This is an example:

5. Now, to calculate the mean (or average) for your first data set you are going to type the

following formula into the “mean” cell for your first plant: =AVERAGE(B2:F2) and hit

enter (you can also click on the first data point/cell and hold and drag across the row to

highlight the values you want to use instead of typing in the B2:F2 manually). The mean

will be calculated for you using the formula you entered:

6. In order to calculate the mean for the rest of the data sets, you are going to copy and

paste that formula to the cells below. Click on the cell where you entered the formula

for the first plant (G2) and hit “CTRL C” to copy it. Now highlight the cells below by

clicking and dragging down the column and hit “CTRL V” to paste the formula

(alternatively you can click on the cell with the original formula and mouse over the

bottom right corner until you see a “+” sign, then click and drag down the column and it

will copy and paste the formula to all the cells below it). Now the mean should be

calculated for each data set.

7. Next you are going to calculate the standard deviation for each data set. For the first

plant, type the following formula into the “std dev” cell: =STDEV(B2:F2) and hit enter.

Copy and paste this formula for the other data sets just like you did for the mean

formula:

8. Next you are going to calculate the standard error for each data set. For the first data

set, type the following formula into the “std error” cell: =H2/SQRT(5) and hit enter.

Copy and paste this formula for the other data sets just like you did for the mean

formula:

9. Now you need to double your Standard Error of the Mean (or SEM) values so that you

can add error bars to 95% confidence (+/-2 SEM values) to your graph later. Add

another column to the right of “Std. Error” with a label named “SEM x 2.” For the first

plant, enter the following formula into the cell: I2*2 and hit enter. Copy and paste this

formula for the other data sets:

10. Finally, you are going to graph your data. We are only going to graph the mean leaf

length for each plant so highlight the plant type and mean columns ONLY as shown

below (click and drag to highlight the entire list of plants, then hold down the CTRL

button as you click and drag down the mean column):

11. Now click on the “Insert” option from the tool bar at the top of the screen and select the

“Chart” option from the drop down menu:

12. The following screen will pop up, under the first drop-down menu labeled chart type

make sure that column chart (bar graph) is selected. Then scroll down to the bottom

and click the “Switch rows/columns” box - this should cause each bar to change to a

different color (instead of all one color). This is really important, each bar must be a

different color in order to enter different error bar values for each plant type. It should

look like the example below:

NOTE: If you close the chart editor window at any point in time and need to re-open it,

click on your graph and scroll over the top right corner until you see three dots - click edit

chart to re-open it.

13. Now click on the “Customize” tab at the top and then click “Chart & Axis Title” to add or

change the title and labels on your graph. “Chart Title” will automatically show up in the

first drop-down menu, click in the “Title text” box below to change it to “Mean leaf

length in five different plant species to 95% Confidence.” The “to 95% Confidence”

phrase means that you will add error bars that are +/-2 standard error of the mean (or

SEM) values; it literally means that if there is no overlap in error bars between two

different mean values then you are 95% sure that the means are actually different from

one another. Then change the drop-down to “Horizontal axis title” and change it to

“Plant type.” The “Vertical axis” or y axis should be labeled “Mean leaf length (cm).”

14. Now you will need to add error bars (+/-2 SEM) for each data set using your doubled

standard error (or SEM x 2) values. Under “Customize” in your Chart editor window

click on “Series” and then change the first drop-down from “Apply to all series” to the

name of your first plant type.

15. Scroll down and click in the box next to “Error bars.” Change the drop down menu

underneath from “Percent” to “Constant” and then type in the SEM x 2 value for that

type of plant from your data table. The error bar should then show up on your graph.

16. Scroll back up and change the first drop-down menu to the next plant type and then

repeat step 15. Continue until error bars have been added.

17. Now your graph is complete. The last thing you need to do is share your Google Sheet

with me. Click on the “Share” button in the upper right corner and type in my email

address ctucker@wall.k12.nj.us in the box called “Add People and Groups” and change

the drop down menu on the right from “Editor” to “Commenter.” Then click the “Send”

button below. This must be shared by 7:20AM on Friday September 11th to be

submitted on time.