Q1. If 2% of all high school graduates in the USA are admitted in Harvard university , and if 300,000 students are expected to graduate from high school this year.
The mean and the standard deviation of the number of students that will be admitted to Harvard university next year?
The probability of admitting 5000 or fewer students in Harvard university next year?
Q2. A random sample of 40 smoking people is classi?ed in the following table:
|
Age
|
Frequency
|
|
10 - 20
|
4
|
|
20 - 30
|
6
|
|
30 - 40
|
12
|
|
40 - 50
|
10
|
|
50 - 60
|
8
|
The mean age of this group of people ?
Q3. In measuring the center of the data from a skewed distribution, the median would be preferred over the mean for most purposes because: (choose an answer)
a. the median is the most frequent number while the mean is most likely
b. the mean may be too heavily in?uenced by the larger observations and this gives too high an indication of the center
c. the median is less than the mean and smaller numbers are always appropriate for the center
d. the mean measures the spread in the data
e. the median measures the arithmetic average of the data excluding outliers.
Q4. Suppose a random sample of 100 12-year-old boys were chosen and the heights of these 100 boys recorded. The sample mean height is 64 inches, and the sample standard deviation is 5 inches. You may assume heights of 12-year-old boys are normally distributed. Which interval below includes approximately 95% of the heights of 12-year-old boys? (choose an answer)
a. 63 to 65 inches.
b. 39 to 89 inches.
c. 54 to 74 inches.
d. 59 to 69 inches.
e. Cannot be determined from the information given.
f. Can be determined from the information given, but none of the above choices is
Q5. Suppose that the age among elderly is distributed as follows:
|
age
|
Male
|
Female
|
|
65 - 69
|
5
|
10
|
|
70 - 74
|
9
|
17
|
|
75 - 79
|
11
|
18
|
|
80 - 84
|
8
|
12
|
|
85 +
|
4
|
6
|
The best display for showing the relationship between two categorical variables is the: (MCQ)
A) frequency polygon.
B) boxplot.
C) scatterplot.
D) contingency table.
Q6. The standard normal probability distribution: (choose an answer)
a. is a special case of the normal probability distribution.
b. has a mean equal to 0 and a standard deviation equal to 1.
c. measures the distance from the mean in units of the standard
d. all of the above
Q7. A normal probability distribution is completely described by (choose an answer)
a. its mean. b. its standard deviation.
c. its mean and standard deviation. d. none of the above.