Question

18. A researcher is comparing two sets of instructions for assembling a bicycle. Of the 14 people using the first set of instructions, only 5 were able to assemble the bike completely in 30 minutes. Of the 14 people using the second set of instructions, 9 completed assembly in 30 minutes. Convert the data into a form suitable for the phi-coefficient and compute the phi-correlation for these data.  Be sure to show all formulas with symbols (and plug in numbers), steps, processes and calculations for all steps and all parts of all answers.

Answer 1

		Able	Were not able	Total
First Set	Observed	5	9	14
	Expected	4.26	9.74	14.00
	O - E	0.74	-0.74	0.00
	(O - E)² / E	0.13	0.06	0.18
Second Set	Observed	9	23	32
	Expected	9.74	22.26	32.00
	O - E	-0.74	0.74	0.00
	(O - E)² / E	0.06	0.02	0.08
Total	Observed	14	32	46
	Expected	14.00	32.00	46.00
	O - E	0.00	0.00	0.00
	(O - E)² / E	0.18	0.08	0.26
		.26	chi-square
		1	df
		.6067	p-value

Phi correlation coefficient =