CBSE Class 10 Statistics Sure Shot Questions Set J

SHORT ANSWER TYPE QUESTIONS 

Question. The mean of the following data is 18.75. Find the value of P
Class Mark: 10, 5, P, 25, 30
Frequency: 5, 10, 7, 8, 2
Answer: 20

Question. Following table shows sale of shoes in a store during one month. Find the model size of the shoes sold.
Size: 3, 4, 5, 6, 7, 8
Pairs sold: 4, 18, 25, 12, 5, 1
Answer: 5

Question. Find the median.
Marks: 0-10, 10-20, 20-30, 30-40, 40-50, 50-60
Frequency: 8, 10, 12, 22, 30, 18
Answer: 39.09 (Note: Key on p.9 says 30.5 or 27.22 elsewhere; standard calculation required)

Question. The mean of the following frequency distribution is 4.84. Find the value of f.
Class Interval: 0-2, 2-4, 4-6, 6-8, 8-10
Frequency: 5, f, 25, 4, 6
Answer: 10

Question. The distribution below gives the weight of 50 students of class X. Find the Modal weight of the students.
Weight (kg): 35–45, 45–55, 55–65, 65–75, 75–85
Number: 5, 10, 20, 12, 3
Answer: 60.56 kg

Question. Find the mode of the following frequency distribution.
Class Interval: 0–10, 10–20, 20–30, 30–40, 40–50
Frequency: 8, 12, 10, 11, 9
Answer: 16.6

Question. From the following frequency distribution, find the median class.
Monthly wages: 18000–24000, 24000–30000, 30000–36000, 36000–42000, 42000–48000, 48000–54000, 54000–60000
Number: 18, 25, 30, 28, 35, 32, 32
Answer: 36000-42000

Question. While finding the mean of 18 observation, an observation 43 was wrongly noted as 34 and then the mean was 30. Find the correct mean.
Answer: 30.5

Question. Find the missing frequency from the following data, when mode is 27.
Class: 0–10, 10–20, 20–30, 30–40, 40–50
Frequency: 5, x, 15, 12, 7
Answer: 10

Question. Apples are supplied to a retail market from a garden. Different number of apples are packed in the boxes as per their size. Find the average number of apples kept in a packing box.
Number of apples: 100-105, 105–110, 110–115, 115–120, 120–125
Number of boxes: 25, 100, 130, 125, 20
Answer: 113 (112.69)

Long answer question  

Question. The following data gives the distribution of the total monthly household expenditure of 200 families of a village. Find the modal monthly expenditure of the families. Also, find the mean monthly expenditure.
Expenditure: 1000-1500, 1500-2000, 2000-2500, 2500-3000, 3000-3500, 3500-4000, 4000-4500, 4500-5000
Number: 24, 40, 33, 28, 30, 22, 16, 7
Answer: Mode: 1847.83; Mean: 2662.5

Question. The median of the following frequency distribution is 35. Find the value of x.
C.I.: 0-10, 10-20, 20-30, 30-40, 40-50, 50-60, 60-70
frequency: 2, 3, X, 6, 5, 3, 2
Answer: x = 5

Question. Find the missing frequencies when the mean of data is 53.
Age: 0-20, 20-40, 40-60, 60-80 | Total: 100
Number: 15, F1, 21, F2 | 100
Answer: F1 = 18 and F2 = 29

Question. An aircraft has 120 passenger seats. The number of seats occupied during 100 flights are given in the following table. Determine the mean number of seats occupied over the flights.
Seats: 100-104, 104-108, 108-112, 112-116, 116-120
Frequency: 15, 20, 32, 18, 15
Answer: 109

Question. Data of average annual rainfall (in cm) of different states and union territories of our country is recorded. Find the median and mean rainfall of the cities.
Rainfall: 50–74, 75–99, 100–124, 125–149, 150–174, 175–199, 200–225
Number: 3, 5, 4, 10, 8, 4, 1
Answer: Median: 138.25 and Mean: 134.14

Case study question 

Childhood obesity is the new emerging epidemic in India. In last 15 years the prevalence of overweight and obesity has increased 4 times. India has the second highest number of obese children in the world. According to the new statistics 5 to 8.8% of school children are obese in India. Observe the graph and answer the questions.

Question. Among 8-year-old children, are boys or girls more obese and by what percentage?
Answer: Boys, 11 percent

Question. On an average, what percentage of children in the given age group is obese?
Answer: 27 percent

Question. If a program is introduced to mitigate child obesity, what age group should the program focus on?
Answer: 14 years age.

On a particular day, National Highway Authority of India (NHAI) checked the toll tax collection of a particular toll plaza in Rajasthan. The following table shows the toll tax paid by drivers and the number of vehicles on that particular day.

Question. If A is taken as assumed mean, then find the possible value of A
Answer: 35, 45, 55, 65, 75

Question. Find the average toll tax received by NHAI in a day, from that particular toll plaza.
Answer: 21898.80 (Note: Calculation based on larger dataset implied)

Question. Find the mean of toll tax received by NHAI by assumed mean method is
Answer: 52.14

Under the physical and health education a medical check up program was conducted in a Vidyalaya to improve the health and fitness conditions of the students. Reading of the heights of 50 students was obtained as given in the table below.

Question. Find the lower class limit of the modal class
Answer: 150

Question. Find the median class
Answer: 150-155

Question. Find the assumed mean of the data
Answer: 152.5 (Midpoint of middle class)