Steven is an anthropology student who collected data on the behavior of children of immigrants and children of non-immigrants in a playground setting. He found that children of immigrants spent an average of 16.2 minutes (SD = 20.2, n = 44) per hour playing with adults, while children of non-immigrants spent an average of 19.9 minutes (SD = 6.0, n = 113) per hour playing with adults.

a. Explain why an unpaired-samples t-test is appropriate for these data.

b. What is the null hypothesis for these data?

c. What is the α for this example?

d. Is a one- or a two-tailed hypothesis appropriate for this NHST?

e. Given your response to item (d),what is the appropriate alternative hypothesis for this example?

f. Calculate the degrees of freedom for the data.

g. Find the tcrit value.

h. Calculate the pooled standard deviation and the pooled variance for these data.

i. Calculate the tobs value for the data.

j. Should you reject or retain the null hypothesis?

k. Find a p-value for this example.

l. Should Steven worry about Type I or Type II error?

m. Calculate and interpret Cohen’s d for this example.

n. Do the data in this example violate any assumptions? If so, which one(s)?