Statistics & Probability
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Q. A data set has values: 10, 12, 14, 16. What is the variance? (2021)
Q. A data set has values: 2, 4, 4, 4, 5, 5, 7, 9. What is the variance? (2021)
Q. A group of students has an average age of 20 years. If a new student aged 22 joins the group, what will be the new average age if there were originally 15 students?
Q. A group of students has an average height of 150 cm. If one student leaves the group and the average height becomes 148 cm, what is the height of the student who left?
Q. A group of students has an average height of 160 cm. If one student with a height of 170 cm leaves, what will be the new average height if the group size was 10?
Q. A group of students has an average score of 75. If one student with a score of 90 leaves, what will be the new average if the group size is 10?
Q. A group of students reported the number of hours they studied last week: 2, 3, 2, 4, 5, 2, 3. What is the mode?
Q. A group of students reported the number of languages they speak: 1, 1, 2, 2, 3, 3, 3, 4. What is the mode?
Q. A group of students scored the following marks in a test: 45, 50, 50, 55, 60, 50, 70. What is the mode of the scores?
Q. A jar contains 5 green, 3 yellow, and 2 blue marbles. If one marble is drawn at random, what is the probability that it is either green or yellow?
Q. A jar contains 5 green, 7 yellow, and 8 blue marbles. If one marble is drawn at random, what is the probability that it is either green or yellow?
Q. A jar contains 5 red, 3 blue, and 2 yellow marbles. If one marble is drawn, what is the probability that it is either red or yellow?
Q. A jar contains 5 red, 3 blue, and 2 yellow marbles. What is the probability of drawing a yellow marble?
Q. A jar contains 5 red, 3 blue, and 2 yellow marbles. What is the probability of picking a yellow marble? (2023)
Q. A set of numbers has a mean of 15. If one number is removed, the new mean becomes 12. What was the removed number? (2022)
Q. A set of numbers has a mean of 20. If one number is removed, the mean becomes 18. What was the number removed? (2022)
Q. A set of numbers has a variance of 36. What is the standard deviation? (2019)
Q. A set of numbers has the following frequencies: 10 (1), 20 (2), 30 (3), 40 (4). What is the mode of this set? (2021)
Q. A set of numbers is given as follows: 1, 1, 2, 3, 3, 4, 4, 4, 5. What is the mode?
Q. A student scored 70, 80, and 90 in three exams. What score is needed in the fourth exam to achieve a mean of 85?
Q. A student scored 80, 85, 90, and 95 in four subjects. What score does he need in the fifth subject to achieve an average of 90?
Q. A student scores 70, 80, and 90 in three subjects. What is the average score?
Q. A student scores 80, 85, 90, and 95 in four exams. What score does he need in the fifth exam to achieve an average of 90?
Q. A student scores 80, 85, 90, and 95 in four subjects. What is the average score? (2019)
Q. A student scores 80, 85, and 90 in three subjects. If he wants an average of 85, what score does he need in the fourth subject?
Q. A student scores 80, 85, and 90 in three subjects. What score must he achieve in the fourth subject to have an average of 85?
Q. A student scores 80, 90, and 70 in three subjects. If he wants to achieve an average of 85 after scoring in a fourth subject, what score does he need?
Q. A survey of favorite fruits among 20 people resulted in the following counts: Apple (6), Banana (8), Orange (4), Grape (2). What is the mode of the favorite fruits? (2023)
Q. A survey of favorite fruits yielded the following results: Apple, Banana, Apple, Orange, Banana, Apple. What is the mode?
Q. A survey of the number of books read by students resulted in the following data: 1, 2, 2, 3, 3, 3, 4, 5. What is the mode?
