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प्रश्न
Find the class marks of classes 10−25 and 35−55.
उत्तर
Class mark of 10−25
`=(10 +25)/2`
`=35/2`
`=17.5`
Class mark of 35−55
`=(35 + 55)/2`
`=90/2`
`= 45`
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संबंधित प्रश्न
Describe some fundamental characteristics of statistics.
What is primary data?
Which of the two – the primary or the secondary data – is more reliable and why?
Explain the meaning of the term Class-mark.
Explain the meaning of the term Frequency.
Find the mean, median and mode of the following data:
| Class | 0 – 10 | 10 – 20 | 20 – 30 | 30 – 40 | 40 – 50 | 50 – 60 | 60 – 70 |
| Frequency | 4 | 4 | 7 | 10 | 12 | 8 | 5 |
Find the mean, median and mode of the following data:
| Class | 0 – 50 | 50 – 100 | 100 – 150 | 150 – 200 | 200 – 250 | 250 – 300 | 300 - 350 |
| Frequency | 2 | 3 | 5 | 6 | 5 | 3 | 1 |
A survey regarding the heights (in cm) of 50 girls of a class was conducted and the following data was obtained:
| Height in cm |
120 – 130 | 130 – 140 | 140 – 150 | 150 – 160 | 160 – 170 |
| No. of girls |
2 | 8 | 12 | 20 | 8 |
Find the mean, median and mode of the above data.
The following table gives the daily income of 50 workers of a factory:
| Daily income (in Rs) | 100 – 120 | 120 – 140 | 140 – 160 | 160 – 180 | 180 – 200 |
| No. of workers | 12 | 14 | 8 | 6 | 10 |
Find the mean, median and mode of the above data.
Find the class marks of classes 10 -25 and 35 – 55.
The median of 19 observations is 30. Two more observation are made and the values of these are 8 and 32. Find the median of the 21 observations taken together.
Hint Since 8 is less than 30 and 32 is more than 30, so the value of median (middle value) remains unchanged.
If the median of `x/5,x/4,x/2,x and x/3`, where x > 0, is 8, find the value of x.
Hint Arranging the observations in ascending order, we have `x/5,x/4,x/3,x/2,x Median= x/3=8.`
Define primary data and secondary data.
Explain the meaning of the following terms: True Class Limits
Explain the meaning of the following terms: Frequency
The times, in seconds, taken by 150 athletes to run a 110 m hurdle race are tabulated below:
| Class | 13.8 – 14 | 14 – 14.2 | 14.2 – 14.4 | 14.4 – 14.6 | 14.6 – 14.8 | 14.8 – 15.0 |
| Frequency | 2 | 4 | 5 | 71 | 48 | 20 |
The number of athletes who completed the race in less than 14.6 seconds is:
Can the experimental probability of an event be a negative number? If not, why?
The monthly pocket money of ten friends is given below:
₹ 80, ₹ 65, ₹ 35, ₹ 65, ₹ 50, ₹ 30, ₹ 60, ₹ 35, ₹ 65, ₹ 30
What is the lowest pocket money?
