Question: 1. Research indicates that adolescents, especially adolescent girls, experience a drop in self-esteem when they enter their teens. To evaluate this result, a researcher obtains a sample of 9 adolescent girls, all of which are 13 years old. A self esteem test is given to each participant and the average score for the sample is 66. It is known that the distribution of self-esteem scores for the population of pre-teen girls is normal with a mean of 75 and a standard deviation of 12. Using an alpha of .05, determine whether adolescent girls’ self esteem is significantly different from the self-esteem levels for pre-teen girls. Edit
Answer: 1. Null hypothesis: mu=66
Alternative hypothesis: mu not equals to 66.
Z=(x bar -mu)/(sd/sqrt(n))
critical z at alpha =0.05 is 1.96.
Hence computed z(2.7) > critical z(1.96)
we reject null hypothesis.
Alternative is restated.
So, adolescent girls’ self esteem is significantly different from the self-esteem levels for pre-teen girls. Edit
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