Apologia Physics

Today the class worked on Vectors: The Vector Voyage and Walking Vectors activities.  The Walking Vectors should have been done outside, rather than in the basement. The kids ran into walls.  The point was you can shuffle the order of the vectors and still end up in the same spot.  I made five or six cards.  The kids did the activity, shuffled the cards and repeated it.  The walking did not work because, the kids ran into obstacles, such as walls and tables.  We drew the instructions from the cards on to graph paper.  That worked.

We did not begin the Vector Voyage; the kids are completing it for homework.

Statistics: Chapter 2 and Linear Regression

At the beginning of class, the kids did example 3.9 (p.200 textbook) Does Fidgeting keep you slim?  The class entered the data into L1 and L2, graphed the data, calculated the linear regression and displayed the regression with the data.  The kids learned how to turn on Diagnostic or r coefficient.

Do linear regression models frequently or the kids will forget how to enter, graph, calculate, and display linear regressions. 

We reviewed the Mrs. Daniel's WS 2.2  The homework for Tuesday is the Chapter 2 test.  Yes, the worksheet took most of the class period.

Statistics: Two new videos for the Normal Curve

One of the students took two hours to create two videos with instructions for graphing a normal curve and shading under the curve with a TI 84.  Take a look!

Statistics: Normal Curve

Update: There are two new videos with explanations how to graph the normal curve and shade under the curve here.

The first thing we did in class was graph normalpdf, normalcdf, and shadenorm with the graphing calculator.  The point was to understand how to shade different areas under the normal curve by setting upper bound, lower bound, mean, and standard deviation with these exercises or examples.    These examples have the screen shots.  This powerpoint has good instructions.

We spent about 30 minutes explaining that normalpdf (x) must be defined under y=, 1E99 or -1E99 represent infinity on the TI84, normalpdf graphing a standard curve or normal curve, shadenorm uses lower bound, upper bound, mean, and SD, and normal cdf converts a z score into a percentage.  Largely, we set the window and practiced shading.  We only spent a few minutes converting z score to a percentage or percentile.  The point was to learn how to enter the data.  The screen shots provide the answers.

For the remainder of the class, the laptop died.  We talked about a normal curve, defined z score, introduced the z score equation, talked about comparing scores with the SAT and ACT as an example of standardizing two scores with different scales.  Their homework is to complete the overview and summary and the 2.1 worksheet for Friday.


We have a back-up Thinkpad for the seemingly dead laptop up and running.  Fingers crossed it works on Friday.  I am wed to the powerpoint slideshows.

Statistics: Graphing under the normal curve

The class is trying to integrate graphing calculators.  One skill is graphing under a normal curve.  The first step is to draw a normal distribution curve on the graphing calculator..  The link above has the screen shots for each calculation.  Shadenorm shades the specified area.  The TI84 sequence is Shadenorm(lower bound, upper bound, mean, and SD).  The mean for a normal curve is 0 and the standard deviation SD is 1.  To shade the entire normal curve the sequence is Shadenorm(-1E99, 1E99, 1,0) or (-4,4,0,1)  -1E99 or 1-99 represents infinity or is the program on the TI84 for infinity.  I defined the area under a normal curve as having four SDs in either direction from the mean 0.  Left is designated with - and right is +.  These exercises for shading the area under the normal curve and using normcdf to calculate percentage  were very helpful

It took hours and hours to find useful information about how to graph the normal curve and shade under the normal curve.  The exercises are very useful because they have picture!  The information to the right of these screen shots of the shading are normcdf( and calculate percentages.  In order to shade areas under a normal curve you must have the normal curve defined in y=, the window set for X and Y,  before shading.  Once you have y= and the window settings, the sequence is shadenorm(lower bound, upper bound, mean, SD), such as shadenorm(-1E99, -1.67, 0, 1)  Remember to add the boundaries AND the mean (0 for the normal curve) and SD (1 for the normal curve).  The other step I forgot initially was ENTER.  I defined shadenorm( 1.67, 1E99, 0,1) and forgot to hit ENTER.  I kept entering GRAPH. 

Statistics:chapter two Describing Location in a Distribution

We started class by reviewing the Hamburger and Hank Aaron Home Run activities.  We calculated a five point distribution for each (min, max, Q1, mean, Q3) and also the IQR.

Began chapter two by reviewing 2.1 Overview.

Apologia Physics

Today we reviewed the test questions for Module 2.  Everyone got number 7 wrong.  The question asked was to calculate when two vehicles would collide head on if they were driving toward each other.  The key to solving the problem is to add their speeds together before calculating the time to travel the distance.  One student calculated the time for each vehicle to cover the compete distance between the two vehicles.  That did not take into consideration that the vehicles would collide before reaching the end the distance between them.  I assigned another problem from module 2 for the next class so we get more practice with this type of problem.