Learner name:   Assessor name: D Roczniak Issue date: 13/11/17 Submission date: 30/11/17 Submitted on: Programme: NQF Applied science Level 3 Extended Diploma Unit: Unit 6: Investigative Project Assignment reference and title: Assignment 2: Project Planning

Step 1 – collect your equipment Collect your safety equipment Collect your equipment for your investigation Set it up in front of you Take a picture with your phone of your equipment

Step 2 – carry out and analysis Carry out your investigation Record your results in rough on page 3 Calculate a mean for your results Read the information on graphs on page 4 and decide what type of graph you need to draw Get some graph paper and draw a graph for your data

Draw appropriate graphs to help analyse the data to show differences and trends Graph pointers Independent variable at the bottom Dependent variable at the side Use the titles off your table to label your axis Fill at least half a page of A4 Use a regular scale for both axis Little ‘x’ to jot the point Join each ‘x’ with a straight line Do Not join it to ‘0’

Why use Standard Deviation? Choose and carry out an appropriate statistical test. (Pass) Justify the choice of data analysis technique (merit) Why use Standard Deviation? It is a measure that is used to quantify the amount of variation or dispersion of a set of data values. A low standard deviation indicates that the data points tend to be close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the data points are spread out over a wider range of values.

Practice Problem #1: Calculate the standard deviation of the following test data by hand. Use the chart below to record the steps. Test Scores: 22, 99, 102, 33, 57, 75, 100, 81, 62, 29 Step 1 – count the number of values - 10 Step 2 – calculate the mean = 66

Step 3 – calculate Remember: Mean = 66 22 99 10233 57 75 10081 62 29 -44 33 36 -33 -9 9 34 15 -4 -37 1936 1089 1296 81 1156 225 16 1369 8338

Step 4 – divide by the number of values: 8338 ÷ 10 = 833 Step 4 – divide by the number of values: 8338 ÷ 10 = 833.8 You now have

Step 5 - Finally, find the square root of Square root of 8338 = 91 Step 5 - Finally, find the square root of Square root of 8338 = 91.31 Step 6 – analyse: large s, therefore very spread data. Not very reliable.

Practice The data set below gives the prices (in dollars) of cordless phones at an electronics store. 35, 50, 60, 60, 75, 65, 80

Comments on Accuracy pH The true pH of catalase is pH 7. This should be the fastest time or the most oxygen gas collected. Do your results show this to be the case as well? If so that suggests some accuracy. If not it suggests some inaccuracies. Concentration As concentration increases the time taken for the paper disc to fall and rise should increase as there would be more successful collisions between enzyme and substrate. . Do your results show this to be the case as well? If so that suggests some accuracy. If not it suggests some inaccuracies.

Things which ensured accuracy Taking volume readings at eye level Reading from the meniscus Using different syringes for each pH/concentration Choosing the right size syringes to measure the volume – to reduce error in measuring. Justification of method and equipment State why your method choice ensured accuracy. State why your equipment choice ensured accuracy.

Things which may affected accuracy Oxygen dissolves in liquid so some oxygen may have dissolved and not been collected and measured/or accumulated on the disc to make it rise making the rise slower Hydrogen peroxide would be broken down with each repeat affecting the concentration and therefore the reaction. There may have been some contamination by using the same syringe for each pH or concentration of hydrogen peroxide as the same syringes were used. The concentration of catalase in the potato/yeast/beetroot/liver was unknown.

Precision and Reliability Look at your range bars – which is the largest and shows the least precision? Which the smallest and shows the most precision? Link these to reliability. e.g. The range bars at 0.5M are the largest with a range from 135 seconds to 95 seconds. This means the results are the least precise at this value and therefore are the least reliable.

Justifying choice of method in terms of reliability How many repeats did you do? Why do you do more than one measurement for each value? What does this allow? What could you do to improve the reliability further should you do the experiment again?

Validity Did the method allow you to fully investigate the hypothesis? Are your results accurate and reliable? Restate here some experimental design issues or positives that would have affected your validity (you may have already mentioned them in you accuracy section). Also consider the accuracy of equipment.