STA 2025/2026 MAIN EXAM
COMPLETE QUESTIONS WITH
CORRECT ANSWERS UPDATED
2025/2026!!!ALREADY GRADED!!!
1) Based on the central limit theorem, the sampling distribution of the sample
mean becomes more Normal as the sample size ______. - ANSWER ✓
Increases
2) From the central limit theorem, we know that is we draw a SRS from any
population then the sampling distribution of the sample mean will be
EXACTLY Normal. - ANSWER ✓ False
3) Which statement about the Central Limit Theorem is TRUE? - ANSWER ✓
The Central Limit Theorem states that the sampling distribution of the
sample mean is approximately normal for large sample sizes (n>30)
4) The Central Limit Theorem says that if the sample size is large enough -
ANSWER ✓ the distribution of the sample mean gets closer to being shaped
like a normal distribution.
5) Select the correct choice. To apply the CLT, the typical rule of thumb for
setting sample size is greater than or equal to what? - ANSWER ✓ 30
6) Whenever a sampled population is normally distributed or whenever the
conditions of the central limit theorem are fulfilled, the sample mean is a(n):
- ANSWER ✓ unbiased estimator of the population mean, mu, because the
mean of the sampling distribution of the sample mean equals mu.
7) The following two-way contingency table gives the breakdown of the
population in a particular locale according to party affiliation (A, B, C, or
None) and opinion on a bond issue:
8) A person is selected at random. The probability that the person opposes to
the bond issue is ________________.
, A. =0.07 + 0.14 + 0.06 + 0.03
B. =0.09 + 0.12 + 0.03
C. =0.12 + 0.16 + 0.04 + 0.08
D. =0.08 + 0.06 + 0.03
E. =0.09 + 0.12 + 0.03 + 0.06 - ANSWER ✓ E. =0.09 + 0.12 + 0.03 +
0.06
9) The probability that this part is defective and is made from production line 2
is about
A. =8/160
B. =13/160
C. =5/160
D. =8/13
E. =8/90 - ANSWER ✓ A. =8/160
10) Find the probability that the selected person is a Republican or a
female.
A. =(470+480)/1000
B. =(480+530-290)/1000
C. =(470+480-190)/1000
D. =190/1000
E. =(520+470-280)/1000 - ANSWER ✓ =(470+480-190)/1000
11) Given that a randomly selected voter is a female, find the probability
that she is a Republican.
A. =190/470
B. =290/480
C. =190/1000
D. =190/480
E. =240/520 - ANSWER ✓ D. =190/480
12) Find the probability that the selected family has at least 3 children age
18 or under.
A. 0.30
B. 0.10
C. 0.50
D. 0.20
E. 0.40 - ANSWER ✓ E. 0.20
COMPLETE QUESTIONS WITH
CORRECT ANSWERS UPDATED
2025/2026!!!ALREADY GRADED!!!
1) Based on the central limit theorem, the sampling distribution of the sample
mean becomes more Normal as the sample size ______. - ANSWER ✓
Increases
2) From the central limit theorem, we know that is we draw a SRS from any
population then the sampling distribution of the sample mean will be
EXACTLY Normal. - ANSWER ✓ False
3) Which statement about the Central Limit Theorem is TRUE? - ANSWER ✓
The Central Limit Theorem states that the sampling distribution of the
sample mean is approximately normal for large sample sizes (n>30)
4) The Central Limit Theorem says that if the sample size is large enough -
ANSWER ✓ the distribution of the sample mean gets closer to being shaped
like a normal distribution.
5) Select the correct choice. To apply the CLT, the typical rule of thumb for
setting sample size is greater than or equal to what? - ANSWER ✓ 30
6) Whenever a sampled population is normally distributed or whenever the
conditions of the central limit theorem are fulfilled, the sample mean is a(n):
- ANSWER ✓ unbiased estimator of the population mean, mu, because the
mean of the sampling distribution of the sample mean equals mu.
7) The following two-way contingency table gives the breakdown of the
population in a particular locale according to party affiliation (A, B, C, or
None) and opinion on a bond issue:
8) A person is selected at random. The probability that the person opposes to
the bond issue is ________________.
, A. =0.07 + 0.14 + 0.06 + 0.03
B. =0.09 + 0.12 + 0.03
C. =0.12 + 0.16 + 0.04 + 0.08
D. =0.08 + 0.06 + 0.03
E. =0.09 + 0.12 + 0.03 + 0.06 - ANSWER ✓ E. =0.09 + 0.12 + 0.03 +
0.06
9) The probability that this part is defective and is made from production line 2
is about
A. =8/160
B. =13/160
C. =5/160
D. =8/13
E. =8/90 - ANSWER ✓ A. =8/160
10) Find the probability that the selected person is a Republican or a
female.
A. =(470+480)/1000
B. =(480+530-290)/1000
C. =(470+480-190)/1000
D. =190/1000
E. =(520+470-280)/1000 - ANSWER ✓ =(470+480-190)/1000
11) Given that a randomly selected voter is a female, find the probability
that she is a Republican.
A. =190/470
B. =290/480
C. =190/1000
D. =190/480
E. =240/520 - ANSWER ✓ D. =190/480
12) Find the probability that the selected family has at least 3 children age
18 or under.
A. 0.30
B. 0.10
C. 0.50
D. 0.20
E. 0.40 - ANSWER ✓ E. 0.20
