IB Data Analysis Practice 4

To further practice organizing and presenting data, use the following image of random data to create a data table, process the raw data, and present it.  The data was collected using an electronic balance measuring to the tenth of a gram to find the mass of samples from two different populations where each number represents a different individual.  Use the rubric and explanation below to assist in your processing.

Part A: Creating a Table

1. Create a data table for the information below.
2. Tables should be arranged so that rows/columns are labeled.  All rows/columns must have units, uncertainties, and units.
3. All tables must have a title that specifically indicates what is being presented and be sure to include units.

Part B: Calculating Mean and Standard Deviation.

Excel makes it extremely easy to calculate mean and standard deviation very quickly for large data sets.  Calculate both of these in Excel (don’t use a calculator) by watching the following video:

Calculating mean, median, mode, and standard deviation in Excel.

Part C: Create an Appropriate Graph

The information presented is for the mean of two different samples.  Select which type of graph would be best to visualize the data and create a graph.  While the following video is presented using Google Spreadsheets, it’s discussion of types of graphs may also be useful in determining which type of graph to use (Bar, Line, X-Y Scatter, Pie)

Part D: Creating Error Bars on an X-Y Scatter Plot Graph.

Anytime data is collected for a number of samples of the same category, there will almost always be variation in said data.  By using standard deviation, one can calculate standard of the mean as a way to indicate the reliability of measurements as an indicator of the true mean for the entire population.  Using this value and a confidence interval of 95% can be used to show, with 95% confidence, what values would the true mean would be expected to fall within.  Using the calculated standard deviation, standard error of the mean, and 95% confidence interval, add error bars to your graph after watching the following videos:

How to calculate Standard Error of the Mean & 95% Confidence Interval

How to create Excel Error Bars using 95% Confidence Interval

Part E: Conduct a T-Test

When two sets of data are being compared for a difference, it is helpful to calculate a T-Test in order to determine if there is statistically a significant difference between the two sets of data.  Conduct a t-test to determine if there is a significant difference between two samples.

Standard Deviation & T-tests

Part F: Turn-In

Printing graphs or saving them from Excel can sometimes be just as challenging as creating them.  Arrange the data table and graph on two separate pages where one page will include only the graph, the second only the data table (I just want you to have practice doing both for future when data tables get really big).  Below is a video that helps explain how to do this. Upload images of your data tables and graphs below.

Printing & Organizing Data Tables & Graphs from Excel

Assessment: Analysis

 IB Mark Analysis Descriptor 5-6 The report includes sufficient relevant quantitative and qualitative raw data that could support a detailed and valid conclusion to the research question.Appropriate and sufficient data processing is carried out with the accuracy required to enable a conclusion to the research question to be drawn that is fully consistent with the experimental data.The report shows evidence of full and appropriate consideration of the impact of measurement uncertainty on the analysis.The processed data is correctly interpreted so that a completely valid and detailed conclusion to the research question can be deduced. 3-4 The report includes relevant but incomplete quantitative and qualitative raw data that could support a simple or partially valid conclusion to the research questionAppropriate and sufficient data processing is carried out that could lead to a broadly valid conclusion but there are significant inaccuracies and inconsistencies in the processingThe report shows evidence of some consideration of the impact of measurement uncertainty on the analysisThe processed data is interpreted so that a broadly valid but incomplete or limited conclusion to the research question can be deduced 1-2 The report includes insufficient relevant raw data to support a valid conclusion to the research questionSome basic data processing is carried out but is either too inaccurate or too insufficient to lead to a valid conclusionThe report shows evidence of little consideration of the impact of measurement uncertainty on the analysisThe processed data is incorrectly or insufficiently interpreted so that the conclusion is invalid or very incomplete 0 The student’s report does not reach a standard described by the descriptors above.

A full explanation of the lab standard rubric can be found here