The difference between maximum and minimum values of a observation set is called:
Correct Answer:(A) Range
Step-by-step Solution:
Range = Maximum value - Minimum value.
Q2MCQ1 Mark
In a frequency distribution, class mark of a class is 15 and class width is 6. Lower limit of class is:
Correct Answer:(A) 12
Step-by-step Solution:
Lower limit = Class mark - Width/2 = 15 - 3 = 12.
Q3MCQ1 Mark
Bar graphs are drawn with bars of:
Correct Answer:(A) Equal width and uniform gaps
Step-by-step Solution:
Bar graphs have bars of equal width with uniform spacing.
Q4MCQ1 Mark
In a histogram, the area of each rectangle is proportional to:
Correct Answer:(A) Frequency of corresponding class
Step-by-step Solution:
Area of rectangle in a histogram is proportional to class frequency.
Q5Assertion-Reason1 Mark
Assertion (A): In a histogram, there are no gaps between consecutive rectangles.
Reason (R): Histogram is used to represent continuous grouped frequency distribution.
Correct Answer:(A) Both (A) and (R) are true and (R) is the correct explanation of (A).
Step-by-step Solution:
Both A and R are true and R explains A.
Q6Assertion-Reason1 Mark
Assertion (A): Frequency polygon can be drawn with or without drawing a histogram.
Reason (R): Class marks of class intervals are used as x-coordinates in frequency polygon.
Correct Answer:(B) Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
Step-by-step Solution:
Both statements are true facts in statistics.
Q7Short Answer2 Marks
Thirty children were asked about number of hours they watched TV in previous week: 1, 6, 2, 3, 5, 12, 5, 8, 4, 8, 10, 3, 4, 12, 2, 8, 15, 1, 17, 6, 3, 2, 8, 5, 9, 6, 8, 7, 14, 12. Find range.
Correct Answer:16 hours
Step-by-step Solution:
Max = 17, Min = 1. Range = 17 - 1 = 16 hours.
Q8Short Answer2 Marks
Find class marks of class intervals 10 - 20, 20 - 30, 30 - 40.
Correct Answer:15, 25, 35
Step-by-step Solution:
Class mark = (Lower + Upper)/2. 15, 25, 35.
Q9Short Answer2 Marks
A company manufactures car batteries. Lifetimes (in yrs) of 6 batteries are 2.6, 3.0, 3.7, 3.2, 2.2, 4.1. Find mean lifetime.
Correct Answer:3.15 years
Step-by-step Solution:
Sum = 18.9. Mean = 18.9 / 6 = 3.15 years.
Q10Short Answer2 Marks
Construct grouped frequency table for data with class width 5 starting from 0 - 5.
Correct Answer:Table constructed
Step-by-step Solution:
Intervals: 0-5, 5-10, 10-15, 15-20... with tally marks.
Q11Short Answer2 Marks
State difference between Bar Graph and Histogram.
Correct Answer:Difference stated
Step-by-step Solution:
Bar graph is for discrete data with gaps; Histogram is for continuous data with no gaps.
Q12Long Answer3 Marks
A random survey of number of children in different age groups playing in a park was found: Age (1-2: 5, 2-3: 3, 3-5: 6, 5-7: 12, 7-10: 9, 10-15: 10). Adjust lengths of rectangles for histogram.
Following table gives life time of 400 neon lamps: Life time (300-400: 14, 400-500: 56, 500-600: 60, 600-700: 86, 700-800: 74, 800-900: 62, 900-1000: 48). (i) Represent on histogram (ii) Find lamps with lifetime ≥ 700 hrs.
Correct Answer:(ii) 184 lamps
Step-by-step Solution:
(i) Draw histogram on continuous intervals. (ii) Lamps ≥ 700 hrs = 74 + 62 + 48 = 184 lamps.
Q14Long Answer3 Marks
The runs scored by two teams A and B on first 60 balls in a cricket match are given. Represent data of both teams on same graph using frequency polygons.
Correct Answer:Frequency Polygons drawn
Step-by-step Solution:
Class marks: 3.5, 9.5, 15.5 ... Plot (Class mark, Runs) for Team A and Team B on same axes.
Q15Long Answer3 Marks
100 surnames were randomly picked from a telephone directory. Class intervals (1-4: 6, 4-6: 30, 6-8: 44, 8-12: 16, 12-20: 4). Draw histogram.
Case Study Scenario: A blood donation camp collected blood groups of 30 students: O, A, B, AB, O, A, O, B, A, O, O, A, AB, O, A, O, O, AB, B, A, O, B, A, O, O, A, B, O, F, O.
Question: Find most common and rarest blood group.
Correct Answer:Most common: O (12), Rarest: AB (3)
Step-by-step Solution:
Frequency table: O = 12, A = 9, B = 6, AB = 3. Most common is O, rarest is AB.
Q17Case Study4 Marks
Case Study Scenario: Relative humidity (in %) of a city for 30 days was recorded: 98.1, 98.6, 99.2, 90.3, 86.5, 95.3, 92.9, 96.3, 94.2, 95.1, 89.2, 92.3, 97.1, 93.5, 92.7, 95.1, 97.2, 93.3, 95.2, 97.3, 96.2, 92.1, 84.9, 90.2, 95.7, 98.3, 97.3, 96.1, 92.1, 89.0.
Question: Find range of data and season it represents.
Correct Answer:Range = 14.3 %, Represents Rainy Season
Step-by-step Solution:
Max = 99.2 %, Min = 84.9 %. Range = 99.2 - 84.9 = 14.3 %. High humidity indicates Rainy Season.
Q18PYQ5 Marks
Following are marks obtained by 50 students in mathematics test out of 100: Construct grouped frequency table with class size 10 starting 0-10.
Correct Answer:Frequency Table constructed
Step-by-step Solution:
Class intervals: 0-10, 10-20, 20-30... 90-100. Tally marks and frequencies computed.
Q19PYQ5 Marks
Given data of expenditure of a family on various heads per month: House Rent ₹4000, Food ₹6000, Education ₹3000, Electricity ₹1000, Savings ₹2000. Draw bar graph.
Correct Answer:Bar Graph drawn
Step-by-step Solution:
Bars of equal width drawn for each head with heights proportional to expenditure.
Q20PYQ5 Marks
Number of hours 40 workers spent working in a week: Draw histogram for data (30-35: 3, 35-40: 8, 40-45: 14, 45-50: 9, 50-55: 4, 55-60: 2).
Correct Answer:Histogram drawn
Step-by-step Solution:
Continuous class intervals with heights equal to frequencies 3, 8, 14, 9, 4, 2.
