Easy Level Worksheet
Very Short Answer Questions (1 Mark Each)
(1) Define the term "mean" of a data set. Mean is the
Perfect! Mean =
(2) What is the formula for calculating the median of a grouped data? Median = l +
Excellent! This is the standard median formula for grouped data.
(3) What is the class mark of a class interval 20–30? Class mark =
Perfect! Class mark is the midpoint of the class interval.
(4) Find the class width of the class 40–50. Class width =
Correct! Class width is the difference between upper and lower limits.
(5) State the formula for mode using the empirical relation between mean, median, and mode. Mode =
Excellent! This is the empirical relationship for moderately skewed data.
Short Answer Questions (2 Marks Each)
Note: Answer each question with steps and explanation, in 2-3 sentences. Write down the answers on sheet and submit to the school subject teacher.
(1) The marks obtained by 5 students in a test are: 10, 15, 20, 25, 30. Find the mean. Mean =
Perfect! The mean marks is 20.
(2) Find the median of the following data: 5, 10, 15, 20, 25 Median =
Excellent! For odd number of observations, median is the middle value.
(3) Calculate the class mark for the class interval 60–70. Class mark =
Perfect! Class mark represents the center of the class interval.
(4) If the mean of 6 numbers is 12, find the sum of all numbers. Sum =
Excellent! Used the mean formula to find the sum.
(5) The mode of the data 2, 3, 3, 5, 6 is: Mode =
Perfect! Mode is the most frequently occurring value.
(6) Write any one advantage of using mean in statistics.
Long Answer Questions (4 Marks Each)
Note: Answer each question with steps and explanation. Write down the answers on sheet and submit to the school subject teacher.
(1) Find the mean of the following data using the direct method: Class intervals: 0–10 (5), 10–20 (8), 20–30 (15), 30–40 (7), 40–50 (5). Mean =
Excellent! Systematic application of the direct method.
(2) The following table shows the marks obtained by 40 students in a test. Calculate the median: Marks: 0–10 (5), 10–20 (8), 20–30 (12), 30–40 (10), 40–50 (5). Median =
Perfect! Median ≈ 25.83 marks.
(3) Find the mode of the following data using the formula: Class intervals: 10–20 (6), 20–30 (8), 30–40 (12), 40–50 (5), 50–60 (3). Mode =
Excellent! Mode ≈ 33.64 using the standard formula.
Part B: Objective Questions (1 Mark Each)
Choose the correct answer and write the option (a/b/c/d)
(1) The average of the numbers 2, 4, 6, 8, 10 is:
(a) 5 (b) 6 (c) 7 (d) 8
Correct! Average =
(2) The median of 3, 5, 7 is:
(a) 4 (b) 5 (c) 6 (d) 7
Correct! For 3 values, median is the middle value = 5.
(3) The mode of the data 2, 3, 4, 4, 5 is:
(a) 2 (b) 3 (c) 4 (d) 5
Correct! 4 appears twice, more than any other value.
(4) Class width of the class interval 10–20 is:
(a) 10 (b) 15 (c) 5 (d) 20
Correct! Class width = Upper limit - Lower limit = 20 - 10 = 10.
(5) Class mark of the class 30–40 is:
(a) 30 (b) 35 (c) 40 (d) 25
Correct! Class mark =
(6) The sum of the observations divided by the number of observations gives the:
(a) Mode (b) Median (c) Mean (d) Range
Correct! This is the definition of arithmetic mean.
(7) The median is the value of the:
(a) Most frequent observation (b) Middle observation (c) Least observation (d) Average of data
Correct! Median is the middle value when data is arranged in order.
(8) In a frequency distribution, the class having the highest frequency is called:
(a) Modal class (b) Median class (c) Upper class (d) Lower class
Correct! Modal class contains the mode and has the highest frequency.
(9) The mean is affected by:
(a) Extreme values (b) Median (c) Mode (d) None
Correct! Mean is sensitive to outliers and extreme values.
(10) A bar graph is used to represent:
(a) Qualitative data (b) Ungrouped data (c) Grouped data (d) All types of data
Correct! Bar graphs are typically used for ungrouped (discrete) data.
Basic Statistics Challenge
Determine whether these statements about basic statistics are True or False: