Question

1a.

A student wonders if people from small towns are friendlier than the general population. To test this hypothesis he gives 100 people a friendliness survey. The population mean for this survey is 50 with a standard deviation of 12. The mean for his sample is 52.5. Compute a z for a sample mean to determine if his hypothesis was supported. Use α = .05, one tailed. Compute the effect size for this study.

	a.	.03
	b.	.21
	c.	1.2
	d.	2.08

1b.

A student wonders if people from small towns are friendlier than the general population. To test this hypothesis he gives 100 people a friendliness survey. The population mean for this survey is 50 with a standard deviation of 12. The mean for his sample is 52.5. Compute a z for a sample mean to determine if his hypothesis was supported. Use α = .05, one tailed.

Describe the size of the effect.

	a.	small
	b.	medium
	c.	large

Answer 1

Answer:-

Given That:-

A student wonders if people from small towns are friendlier than the general population. To test this hypothesis he gives 100 people a friendliness survey. The population mean for this survey is 50 with a standard deviation of 12. The mean for his sample is 52.5. Compute a z for a sample mean to determine if his hypothesis was supported. Use α = .05, one tailed.

From the given information,

z= (52.5-50)/(12/squareroot (100))

z=2.5/1.2

z=2.0833

And

Given:-

n = 100

Consider,

1a)

Effect size =  

=

Effect size = 0.21

i.e, option b) is correct.

1b)

As effect size is near to 0.2,

Hence, it is small size of the effect.

i.e, option a) is correct.