Question

A researcher measures the relationship between the number of interruption during a case and time spent on task in minutes). Answer the following questions based on the results provided 11 6 10 12 5 30 Part Compute the Pearson correlation coefficient (Round your awer to three decimal places) Part Multiply each measurement of interruption times 3 and recalculate the correlation coefficient Round your answer to the decimal places) Part Divide each measurement in half for time spent on task and recalculate the correlation coefficient. (Round your answer to the decimal places) Part True or false Multiplying or dividing a positive constant by one set of scores UX or does not change the correlation coeficient Note Use your answers in (a) to (c) to answer true or false True

Answer 1

Part a) Pearson's correlation coefficient = -0.851

{Using MS-Excel command, =CORREL(array1, array2) }

Part b) Pearson's correlation coefficient= -0.851

Part c) Pearson's correlation coefficient= -0.851

Part d) True.

(Since, we can see from part a) to c) correlation coefficient remains same, it is not affected by multiplying and dividing by a positive constant on one of the set X or Y)

fx C2464:C2467 ) B С D X 2454 2455 2456 2457 2458 part a) 2459 2460 Let, X: No. of interruption Y: Time spend on task 2461 2462 2463 Х 2464 у 15 40 =CORREL( B2464:B2467 C2464:C2467 ) 2465 11 6 9 5 2466 17 2467 30 2468 r= -0.851 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 + Sheet1 Sheet2

fx C2464:C2467) B C D X 2456 2457 2458 part b) 2459 2460 Let, X: No. of interruption Y: Time spend on task 2461 2462 2463 3x 2464 33 I=CORREL( B2464:B2467 , C2464:C2467 ) 2465 18 y 15 40 17 30 2466 27 2467 15 2468 r= -0.851 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 + Sheet1 Sheet2

fx C2464:C2467 ) B C D X 2454 2455 2456 2457 2458 part c) 2459 2460 Let, X: No. of interruption Y: Time spend on task 2461 2462 2463 X y/2 7.5 2464 11 =CORREL( B2464:B2467 , C2464:C2467 ) 2465 6 2466 9 20 8.5 15 2467 5 2468 r= -0.851 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 + Sheet1 Sheet2