Week 3 Homework

1)Answer questions below:

a)A researcher makes a prediction regarding the direction of mean differences between an experimental and control group.When deciding on asample size should s(he) use a 'one' or 'two' tailed test in her decision?___________

b)When raw scores are converted to standard scores, the resulting distribution has a mean equal to ________and a standard deviation equal to what_______?

c)The null hypothesis assumes there is no relationship between variables.(True/ False)

d)When a researcher rejects the 'null hypothesis' it means there are statistically significant results indicating a relationship between the variables.(True/ False)

2)A young man's score on an anxiety scale is 31.The population mean score is 27.3 and s.d. is 10.2.Find his 'z' score and report his corresponding percentile rank.Use Kim & Mallory pps. 121-125 for guidance.