1. Find the area under the normal curve between z = 0 and z = 1.63.
Answer: z = 0 and z = 1.63
= 0.4484
2. On a final examination in Mathematics, the mean was 76 and the standard deviation was 5.
Determine the standard score of a student who received a score of 88 assuming the scores are normally
distributed.
x −mean
¿
Answer: Standard Deviation
Mean = 76 88−76
¿
5
Standard Deviation = 5
12
¿
x = 88 5
= 2.4
3. What percent of the area under the normal curve is between z = - 1.00 and z = 1.00?
Answer: z = - 1.00 and z = 1.00
-1.00 = 0.3413 and 1.00 = 0.3413
= 0.3413 + 0.3413
= 0.6826
= 68.26 %
4. Find the area under the normal curve between z = 0 and z = - 1.78
Answer: z = 0 and z = -1.78
= 0.4625
5. Anthony Vincent tosses an unbiased coin. He receives Php 100 if a head appears and he pays Php 40 if
a tail appears. Find the expected value and the variance of his gain.
x P(x) xP(x) x2P(x)
-40 0.5 -20 800
100 0.5 50 5,000
= 30 = 5,800
Answer:
a. expected value = [xP(x)]
= 30
The expected value is Php 30
b. variance of his gain = [x2P(x) - ([xP(x)])^2
= 5,800 - (30)^2
The variance of his gain is Php 4,900
6. In a given normal distribution, the population mean is 60 and the population standard deviation is 3.2.
Find the corresponding score of 68
Answer: x −mean
¿
Standard Deviation
Mean = 60
68−60
¿
Standard Deviation = 3.2 3.2
x = 68 8
¿
3.2
= 2.5
7. In a given normal distribution, the population mean is 60 and the population standard deviation is 3.2.
Find the corresponding score of 56.
Answer: x −mean
¿
Standard Deviation
Mean = 60
56−60
¿
Standard Deviation = 3.2 3.2
x = 56 −4
¿
3.2
= -1.25
PS. NAKARAWAT AKON BAYAD NA
TWICE ALBUM (FEEL SPECIAL)