ICA #8
1.
Comment whether each of the boldface numbers is a parameter or a
statistic?
§
A study of 1225 incident breast cancer cases found that survival varied
greatly by stage of disease at diagnosis. The median 7-year survival rate for
stage I breast cancer was
92%
. For stage II breast cancer, the 7-year survival
rate was
71%
. For stage II breast cancer, the survival rate was
39%
. For
stage IV, the survival rate was
11%
.
Statistics
§
Data from the complete enumeration of a standard metropolitan area (SMA)
indicate that
12%
of the inhabitants are African American. A telephone
survey based on random-digit–dialing of individuals from this SMA found
that
8%
of the respondents were African American.
Parameter= 12%
Statistic= 8%
2.
Wechsler Adult Intelligence Scale (WAIS) scores vary according to a
Normal distribution with
μ
= 100 and
σ
= 15. Find the mean and SD of the
sampling distribution of a mean based on an SRS (Simple Random Sample)
of 10 such scores?
15/square root 10= 4.74
X~ N(100, 4.74).
