# MAT117 Home

Course syllabus

#### Online Homework

Homework Videos

HW videos for the questions listed below are posted in the playlist "MAT117 Applied Statistics" on https://www.youtube.com/user/ProfessorEnsley. If you have a YouTube or Google account, you can subscribe to this channel and get emails when new videos are added.

• Online 02 (Sections 2.1 & 2.2) Problem #10
• Online 03 (Sections 2.3 & 2.4) Problem #07
• Online 03 (Sections 2.3 & 2.4) Problem #12
• Online 07 (Sections 3.2 & 3.3) Problem #1
• Online 07 (Sections 3.2 & 3.3) Problem #2
• Online 07 (Sections 3.2 & 3.3) Problem #3
• Online 09 (Section 6.2) Problem #1
• Online 09 (Section 6.2) Problem #2
• Online 09 (Section 6.2) Problem #6
• Online 10 (Section 7.1) Problem #1
• Online 10 (Section 7.1) Problem #3
• Online 10 (Section 7.1) Problem #4
• Online 12 (Sections 9.1 & 9.2) Problem #8
• Online 14 (Section 7.2) Problem #1
• Online 14 (Section 7.2) Problem #2
• Online 14 (Section 7.2) Problem #4
• Online 18 (Section 14.1) Problem #5
• Online 19 (Sections 11.1/11.2) Problem #1
• Online 19 (Sections 11.1/11.2) Problem #8

#### Other Videos

Activities

• Computing Sample Proportions: Individually or in pairs, students roll 3 dice and record "1" if there are three different values and record "0" otherwise. The experiment is repeated 50 times and each person/pair computes a value of p-hat. These values are entered into Excel at the front of the room and a histogram is displayed. This leads into the applet "Visualizing Sample Proportions" listed below.
• Computing Confidence Interval for a Proportion: The above activity is repeated with each student (or pair), with the goal being the calculation of a 90% confidence interval. Then the true value of the parameter (p = 5/9) is given, and the class is polled as to how many had made a "true" statement about p. If care has been taken,  you should see roughly 90% made true statements. This leads into the applet "Visualizing Confidence Intervals for a Proportion" listed below.
• Computing Sample Means: Each student or pair of students takes one sample sheet and finds mean and standard deviation for that sample. Sample means are recorded in a spreadsheet and a histogram is shown. (The population mean and standard deviation are each roughly 20 since the data here is generated by a "rounded" exponential distribution with lambda = 0.05.)This leads into the applet "Visualizing Sample Means" listed below.
• Computing Confidence Interval for a Mean: The above activity is repeated with each student (or pair), with the goal being the calculation of a 90% confidence interval. Then the true value of the parameter (mu = 20) is given, and the class is polled as to how many had made a "true" statement about mu. If care has been taken,  you should see roughly 90% made true statements. This leads into the applet "Visualizing Confidence Intervals for a Mean" listed below.

#### Applets

Flashandmath.com has mathematics applets for many different courses. The following are recent posts of a collection of applets for instructor demonstrations in an introductory statistics course.
• Interactive Histogram. This tool is used in many of the applets on this page. It illustrates the notion of “bin” that is important for understanding both histograms and distributions in general.
• Visualizing Sample Proportions. Simulates experimentally collecting sample proportions and creating a histogram to illustrate the theoretical mean and spread of the sample distribution.
• Visualizing Confidence Intervals for a Proportion. Simulates experimentally collecting sample proportions and forming confidence intervals. The percentage of confidence intervals that contain the true population proportion is shown to illustrate the notion of “confidence level.”
• Visualizing a Sample Mean. Simulates experimentally collecting a single sample (from a population whose distribution is shown) and displaying summary statistics for that sample. Allows the user to repeat the experiment, collecting a set of sample means and even showing a histogram to illustrate the theoretical mean and spread of the sample distribution.
• Visualizing the Distribution of Sample Means. Simulates experimentally collecting sample means and creating a histogram to illustrate the theoretical mean and spread of the sample distribution. The theoretical distribution of the population is provided for comparison.
• Visualizing Confidence Intervals for a Mean. Simulates experimentally collecting sample means and forming confidence intervals. The percentage of confidence intervals that contain the true population mean is shown to illustrate the notion of “confidence level.”
 For more details, contact me by sending e-mail to deensley@ship.edu or by using the information at the right. Doug Ensley Department of Mathematics Shippensburg University Shippensburg, PA 17257 Phone: (717) 477-1431 Fax: (717) 477-4009