ISABELA COLLEGE OF ARTS & TECHNOLOGY, INC.
Tagaran, Cauayan City, Isabela, Philippines
Telefax: (078) 652-1038
Email: icat_97@yahoo.com.ph / info@icat.edu.ph
2nd Quarter Examination
Statistics & Probability
A.Y. 2023-2024
Name:________________________________________________________Score:______________________
I. MULTIPLE CHOICE: Choose the correct answer from the choices given and write the letter of your answer
on the space provided before the number.
____ 1. Which of the following best defines a random variable?
A. A variable that takes on only one fixed value.
B. A variable that is determined by a known, predictable process.
C. A variable that is completely unrelated to any probabilistic outcomes.
D. A variable whose outcome is uncertain and can be mapped to a numerical value.
____ 2. If W is a random variable with a normal distribution, which of the following statements is true regarding
the standard deviation of W?
A. The standard deviation is always equal to the mean.
B. Increasing the standard deviation results in a narrower distribution.
C. The standard deviation uniquely determines the shape of the distribution.
D. The standard deviation is a measure of the spread or variability of the distribution.
____ 3. If a random variable X can take any value within a given range, it is classified as:
A. Continuous
B. Deterministic
C. Discrete
D. Nominal
____ 4. Suppose you roll two fair six-sided dice. Let Y be the sum of the numbers obtained. What type of random
variable is Y?
A. Continuous
B. Deterministic
C. Discrete
D. Nominal
____ 5. For a normal distribution, which of the following statements is true about the mean and median?
C. The mean is always greater than the median.
A. They are always equal.
B. The mean is always less than the median.
D. The relationship varies and cannot be generalized.
____ 6. For a normal distribution, what is the shape of the probability density function (PDF)?
A. Bell-shaped curve
B. Uniform distribution
C. Exponential decay
D. Skewed to the right
____ 7. What is a sampling distribution?
A. The distribution of the entire population.
B. The distribution of sample sizes in a population.
C. The distribution of a random variable in a specific sample.
D. The distribution of sample means or other statistics over many samples.
____ 8. Which of the following sampling methods is most likely to produce a representative sample?
A. Convenience sampling
C. Simple random sampling
B. Purposive sampling
D. Snowball sampling
____9. What is a parameter in statistics?
A. A measure of central tendency.
B. An estimate of the standard deviation.
C. A descriptive measure calculated from a sample.
D. A characteristic or numerical value that describes a population.
___ 10. Which of the following is a measure of central tendency?
A. Median
B. Range
C. Standard Deviation
___ 11. What is the null hypothesis in hypothesis testing?
A. The hypothesis that is always accepted.
B. The hypothesis that is always rejected.
C. A statement that there is no effect or relationship.
D. A statement that there is a significant effect or relationship.
D. Variance
____ 12. In a class of 25 students, the teacher recorded the number of books each student read over the summer.
The data set is {2, 3, 4, 5, 6, 7, 10}. Find the median number of books read.
A. 5 books
B. 6 books
C. 7 books
D. 8 books
____ 13. A group of friends recorded their ages: {25, 28, 30, 32, 40}. Calculate the mode of their ages.
A. 28
B. 30
C. 32
D. No mode
____ 14. A survey asked participants about the number of hours they sleep per night. The data set is {6, 7, 7, 8,
9}. Find the range of the hours of sleep.
A. 2 hours
B. 3 hours
C. 4 hours
D. 5 hours
____ 15. The monthly salaries (in dollars) of a group of employees are: {3000, 3500, 4000, 4500, 6000}. Calculate
the mean salary.
A. $4000
B. $4500
C. $5000
D. $5500
II. PROBLEM SOLVING
16-45. Given below are the scores of Grade 12 PRE BACC in their Statistics and Probability quiz with the number
of students belonging to their score range (frequency).
Scores
f
16-20
12
21-25
25
26-30
37
31-35
26
cf
lb
x
fx
̅
𝒙−𝒙
(𝒙 − 𝒙
̅) 𝟐
̅) 𝟐
𝒇(𝒙 − 𝒙
Questions:
46-50. Compute the mean, standard deviation, and variance.
Prepared by:
Noted by:
EDA MAY C. SIMON, LPT
Subject Teacher
ROSE ANDREA G. BATOON, LPT
Teacher-In-Charge