BIO6X/PM2. General Certificate of Education Advanced Level Examination June Unit 6X A2 Externally Marked Practical Assignment Task Sheet 2

Transcription

1 Centre Number Surname Candidate Number For Examinerʼs Use Tota Task 2 Other Names Candidate Signature Genera Certificate of Education Advanced Leve Examination June 2012 Bioogy BIO6X/PM2 Unit 6X A2 Externay Marked Practica Assignment Task Sheet 2 To be competed before the EMPA Written Test. For submission by 15 May 2012 For this paper you must have: a ruer with miimetre measurements a cacuator. BIO6X/PM2

2 2 Task 2 Introduction Parsnip seeds are very simiar to hogweed seeds but are easier to obtain. In this task you wi ook at the effect of the height at which parsnip seeds are reeased on the horizonta distance they trave. Materias You are provided with parsnip seeds piece of string with a weight tied to it. This is a pumb ine. metre rue or tape measure stand and camp piece of chak 30 cm ruer with miimetre measurements. You may ask your teacher for any other apparatus you need. Method Read the foowing instructions carefuy before you start your investigation. 1. Camp a 30 cm ruer, horizontay, 1 metre above the foor. The free end of the ruer wi be the reease point for your parsnip seeds. Use the pumb ine and piece of chak to put a sma mark on the foor immediatey under the reease point. 2. Drop a parsnip seed from the reease point. Measure the distance from where the parsnip seed ands to the chak mark. 3. Repeat step 2 unti you have data for 20 parsnip seeds. You may assume that this is enough for a statistica test. 4. Repeat steps 1 to 3. This time, reease the parsnip seeds at a height of 0.5 metre above the foor. 5. Record a your resuts in a suitabe tabe. You must decide for yoursef how to standardise the task so that the parsnip seeds are aways reeased in the same way.

3 3 Recording your data Record your raw data in an appropriate tabe in the space beow. Turn over

4 4 Anaysing your data 4 Use a statistica test to anayse your data and test your nu hypothesis. You may use a cacuator and the Students Statistics Sheet that has been provided in this booket. You are provided with a sheet of graph paper. You may use this if you wish. 4(a) State your nu hypothesis. (1 mark) 4(b) Give your choice of statistica test. (1 mark) 4(c) Give a reason for your choice of statistica test. (1 mark)

5 5 Do not write outside the box 4(d) Cacuate the test statistic. Show your working. (1 mark) 4(e) Interpret the test statistic in reation to your nu hypothesis. Use the words probabiity and chance in your answer. (2 marks) END OF TASK 2 6 Turn over

6 You may use this if you wish 6 Do not write outside the box

7 7 AQA Students Statistics Sheet (version 3) What sort of data wi you obtain in your investigation? Measurements Wi your investigation invove taking measurements? Frequencies Wi your investigation invove finding the number of individuas in particuar categories? Wi your investigation invove ooking for associations between different measurements from the same sampe? Wi your investigation invove ooking for differences between mean vaues? χ 2 test Spearman rank correation Standard error and 95% confidence imits Standard error and 95% confidence imits Cacuate the standard error of the mean, SE, for each sampe from the foowing formua SE = SD n where SD = the standard deviation and n = sampe size 95% confidence imits = 2 SE above and beow the mean For use in the ISA and EMPA assessment Turn over

8 8 Do not write outside the box The χ 2 test The chi-square (χ 2 ) test is based on cacuating the vaue of χ 2 from the equation χ 2 = Σ (O E) 2 E where O represents the resuts you observe in the investigation and E represents the resuts you expect. Tabe showing the critica vaues of χ 2 at P = 0.05 for different degrees of freedom Spearman rank correation test Degrees of Critica vaue freedom Cacuate the vaue of the Spearman rank correation, r s, from the equation [ ] r s = 1 6 Σ D2 n 3 n where n is the number of pairs of items in the sampe and D is the difference between each ranked pair of measurements. Tabe showing the critica vaues of r s at P = 0.05 for different numbers of paired vaues Number of pairs Critica vaue of measurements For use in the ISA and EMPA assessment Copyright 2012 AQA and its icensors. A rights reserved.