STAT 1000 Final Exam Q&A Bundle: Multiple Choice
Questions with Correct Answers & Rationales |
2026/2027 Edition
,Descriptive Statistics
1. The mean of 2, 4, 6, 8 is:
A) 4 B) 5 C) 6 D) 7
Answer: B) 5
Rationale: (2 + 4 + 6 + 8) / 4 = 5.
2. The median of 3, 7, 9, 15, 20 is:
A) 7 B) 9 C) 15 D) 20
Answer: B) 9
Rationale: The middle value in the ordered list is 9.
3. The mode of 2, 2, 3, 4, 4, 4, 5 is:
A) 2 B) 3 C) 4 D) 5
Answer: C) 4
Rationale: 4 occurs most often.
4. The range of 12, 7, 15, 3, 9 is:
A) 9 B) 12 C) 15 D) 3
Answer: B) 12
Rationale: Range = maximum − minimum = 15 − 3 = 12.
5. Which measure is most resistant to outliers?
A) Mean B) Median C) Range D) Standard deviation
Answer: B) Median
Rationale: The median depends on position, not extreme values.
6. For 1, 2, 3, 4, 5, 6, 7, 8, the interquartile range is:
A) 3 B) 4 C) 5 D) 6
, Answer: B) 4
Rationale: Q1 = 2.5, Q3 = 6.5, so IQR = 6.5 − 2.5 = 4.
7. A z-score is calculated as:
A) (x + mean) / SD B) (x − mean) / SD C) mean / SD D) SD / mean
Answer: B) (x − mean) / SD
Rationale: A z-score measures how many standard deviations a value is
from the mean.
8. An outlier is often defined as a value below:
A) Q1 − IQR B) Q1 − 1.5(IQR) C) Q3 + IQR D) Q3 − 1.5(IQR)
Answer: B) Q1 − 1.5(IQR)
Rationale: The 1.5 × IQR rule identifies potential outliers.
9. In a right-skewed distribution, the mean is usually:
A) Less than the median B) Equal to the median C) Greater than the median
D) Equal to the mode
Answer: C) Greater than the median
Rationale: Large right-tail values pull the mean upward.
10.A boxplot shows:
A) Only the mean B) Five-number summary C) Only the mode D) Only the
variance
Answer: B) Five-number summary
Rationale: Boxplots display min, Q1, median, Q3, and max.
Probability Basics
, 11.If A and B are mutually exclusive with P(A) = 0.3 and P(B) = 0.5, then P(A or
B) is:
A) 0.15 B) 0.20 C) 0.80 D) 0.50
Answer: C) 0.80
Rationale: For mutually exclusive events, P(A or B) = 0.3 + 0.5 = 0.8.
12.If P(A) = 0.25, then P(not A) is:
A) 0.25 B) 0.50 C) 0.75 D) 1.00
Answer: C) 0.75
Rationale: Complement rule: 1 − 0.25 = 0.75.
13.The probability of rolling a sum of 7 with two fair dice is:
A) 1/12 B) 1/6 C) 1/8 D) 1/36
Answer: B) 1/6
Rationale: There are 6 favorable outcomes out of 36.
14.If A and B are independent with P(A) = 0.4 and P(B) = 0.5, then P(A and B) is:
A) 0.10 B) 0.20 C) 0.90 D) 0.45
Answer: B) 0.20
Rationale: For independent events, multiply: 0.4 × 0.5 = 0.2.
15.If P(A) = 0.6, P(B) = 0.4, and A and B are independent, P(A or B) is:
A) 0.24 B) 0.76 C) 1.00 D) 0.64
Answer: B) 0.76
Rationale: P(A or B) = 0.6 + 0.4 − 0.24 = 0.76.
16.The probability of drawing a heart from a standard deck is:
A) 1/2 B) 1/4 C) 1/13 D) 1/52
Questions with Correct Answers & Rationales |
2026/2027 Edition
,Descriptive Statistics
1. The mean of 2, 4, 6, 8 is:
A) 4 B) 5 C) 6 D) 7
Answer: B) 5
Rationale: (2 + 4 + 6 + 8) / 4 = 5.
2. The median of 3, 7, 9, 15, 20 is:
A) 7 B) 9 C) 15 D) 20
Answer: B) 9
Rationale: The middle value in the ordered list is 9.
3. The mode of 2, 2, 3, 4, 4, 4, 5 is:
A) 2 B) 3 C) 4 D) 5
Answer: C) 4
Rationale: 4 occurs most often.
4. The range of 12, 7, 15, 3, 9 is:
A) 9 B) 12 C) 15 D) 3
Answer: B) 12
Rationale: Range = maximum − minimum = 15 − 3 = 12.
5. Which measure is most resistant to outliers?
A) Mean B) Median C) Range D) Standard deviation
Answer: B) Median
Rationale: The median depends on position, not extreme values.
6. For 1, 2, 3, 4, 5, 6, 7, 8, the interquartile range is:
A) 3 B) 4 C) 5 D) 6
, Answer: B) 4
Rationale: Q1 = 2.5, Q3 = 6.5, so IQR = 6.5 − 2.5 = 4.
7. A z-score is calculated as:
A) (x + mean) / SD B) (x − mean) / SD C) mean / SD D) SD / mean
Answer: B) (x − mean) / SD
Rationale: A z-score measures how many standard deviations a value is
from the mean.
8. An outlier is often defined as a value below:
A) Q1 − IQR B) Q1 − 1.5(IQR) C) Q3 + IQR D) Q3 − 1.5(IQR)
Answer: B) Q1 − 1.5(IQR)
Rationale: The 1.5 × IQR rule identifies potential outliers.
9. In a right-skewed distribution, the mean is usually:
A) Less than the median B) Equal to the median C) Greater than the median
D) Equal to the mode
Answer: C) Greater than the median
Rationale: Large right-tail values pull the mean upward.
10.A boxplot shows:
A) Only the mean B) Five-number summary C) Only the mode D) Only the
variance
Answer: B) Five-number summary
Rationale: Boxplots display min, Q1, median, Q3, and max.
Probability Basics
, 11.If A and B are mutually exclusive with P(A) = 0.3 and P(B) = 0.5, then P(A or
B) is:
A) 0.15 B) 0.20 C) 0.80 D) 0.50
Answer: C) 0.80
Rationale: For mutually exclusive events, P(A or B) = 0.3 + 0.5 = 0.8.
12.If P(A) = 0.25, then P(not A) is:
A) 0.25 B) 0.50 C) 0.75 D) 1.00
Answer: C) 0.75
Rationale: Complement rule: 1 − 0.25 = 0.75.
13.The probability of rolling a sum of 7 with two fair dice is:
A) 1/12 B) 1/6 C) 1/8 D) 1/36
Answer: B) 1/6
Rationale: There are 6 favorable outcomes out of 36.
14.If A and B are independent with P(A) = 0.4 and P(B) = 0.5, then P(A and B) is:
A) 0.10 B) 0.20 C) 0.90 D) 0.45
Answer: B) 0.20
Rationale: For independent events, multiply: 0.4 × 0.5 = 0.2.
15.If P(A) = 0.6, P(B) = 0.4, and A and B are independent, P(A or B) is:
A) 0.24 B) 0.76 C) 1.00 D) 0.64
Answer: B) 0.76
Rationale: P(A or B) = 0.6 + 0.4 − 0.24 = 0.76.
16.The probability of drawing a heart from a standard deck is:
A) 1/2 B) 1/4 C) 1/13 D) 1/52
