MUNTINLUPA SCIENCE HIGH SCHOOL
#999 Buendia Street, Brgy. Tunasan, Muntinlupa City
LEARNING ACTIVITY SHEET #1
A. Directions: Determine whether the variables are discrete or continuous random variables. Write D if the
random variable is discrete and C if it is continuous.
1. The temperature in Taguig City.
2. The weight of each student in the class.
3. The scores of students in a 25-item test.
4. The number of students present in the class.
5. The amount of money earned in an investment.
6. The number of students admitted in a certain school.
7. The family income of the students in a certain school.
8. The distance travelled of the students going to school.
9. The length of TV commercial (in seconds) from 8:00 PM – 11:00 PM.
10. The waiting time of the customers to receive their orders from online shopping.
B. Directions: Identify which of the following statements are true. Write T if the statement is true; otherwise,
change the underlined word or phrase if the statement is false on the space provided before each item number.
1. The discrete random variables are random variables whose value is obtained by measuring.
2. The probability of each value of discrete random variable is between 0 and 1, exclusively.
3. The sum of all the probabilities of a discrete random variable is equal to one.
4. A random variable is a numerical description of an outcome in an experiment.
5. The values of a continuous random variables are in ratio.
C. Directions: Complete the table below and find the mean, variance, and the standard deviation of the following
probability distribution.
1.
x
0
1
2
3
2.
x
2
8
10
P(x)
1
5
2
5
3
10
1
10
P(x)
0.50
0.30
0.20
x · P(x)
x-�
(x – �)2
(x – �)2 · P(x)
x · P(x)
x-�
(x – �)2
(x – �)2 · P(x)
3. An investment will be worth ₱1,000, ₱2,000 or ₱5,000 at the end of the year. The probabilities of these values
are 0.25, 0.60, and 0.15, respectively. Find the mean, variance, and the standard deviation of the worth of the
investment.
4. Jonathan sells new cars for Cindy, Jonathan usually sells the largest number of cars on Wednesday. He has
developed the following probability distribution for the number of cars he expects to sell on particular
Wednesday. Find the mean, variance, and standard deviation of the probability distribution.
Number of Cars Sold
(x)
0
1
2
3
4
Probability
P(x)
0.10
0.20
0.30
0.30
0.10
MUNTINLUPA SCIENCE HIGH SCHOOL
#999 Buendia Street, Brgy. Tunasan, Muntinlupa City
LEARNING ACTIVITY SHEET #2
A. Directions: Identify whether the statement is true. Write T if the statement is true; otherwise, change the
underlined word or phrase if the statement is false.
1. A normal curve is also known as Gaussian curve in honor of Karl Friedrich Gauss.
2. A normal probability distribution is a discrete probability distribution.
3. The graph of the probability density of the normal distribution is a bell-shaped.
4. The arithmetic mean, median, and mode are located at the left of the normal distribution.
5. The arithmetic mean, median, and mode are unequal in a normal distribution.
6. The total area under the normal curve is one.
7. The half of the area under the normal curve is to the right of the center point and other half is to right of it.
8. The normal probability distribution is symmetrical about the mean.
9. The normal distribution is asymptotic to the �-axis.
10. The location of the normal distribution is determined by the percentiles.
11. The dispersion of the distribution is determined by the standard deviation.
12. The tails of the normal curve are extended definitely in opposite directions.
13. The mean of the standard normal distribution is one.
14. The standard deviation of the standard normal distribution is one.
15. Any normal probability distribution can be converted into a standard normal probability distribution.
B. Directions: Find the area under the normal curve of the following � values and sketch the curve.
1. from the mean to � = 1.15.
2. between �1 = −2.03 and �2 = 0.85.
3. between �1 = 1.89 and �2 = 0.52.
4. to the right of � = −0.63.
5. to the left of � = −1.46
E. Solve the given problem.
A weekly income of in a certain online job follows a normal distribution with a mean of ₱1,000 and standard
deviation of ₱100. What is the z value for the income of:
a. who earns ₱1,100 per week?
b. who earns ₱900 per week?