Advertisements
Advertisements
प्रश्न
The data on the number of patients attending a hospital in a month are given below. Find the average (mean) number of patients attending the hospital in a month by using the shortcut method. Take the assumed mean as 45. Give your answer correct to 2 decimal places.
| Number of patients | 10 - 20 | 20 - 30 | 30 - 40 | 40 - 50 | 50 - 60 | 60 - 70 |
| Number of Days | 5 | 2 | 7 | 9 | 2 | 5 |
उत्तर
| Number of patients | Number of Days (fi) |
Mid-value xi |
Assumed Mean A= 45 ∴ d= xi -A |
fi × di |
| 10 - 20 | 5 | 15 | -30 | -150 |
| 20 - 30 | 2 | 25 | -20 | -40 |
| 30 - 40 | 7 | 35 | -10 | -70 |
| 40 - 50 | 9 | 45 | 0 | 0 |
| 50 - 60 | 2 | 55 | 10 | 20 |
| 60 - 70 | 5 | 65 | 20 | 100 |
| Total | 30 | -140 |
Mean = `A + (sumf_i d_i)/(sum f_i)`
` = 45+ ((-140))/30 = 45 - 14/3`
`= (135-14)/3 = 121/3`
` = 40.33`
APPEARS IN
संबंधित प्रश्न
The following distribution represents the height of 160 students of a school.
| Height (in cm) | No. of Students |
| 140 – 145 | 12 |
| 145 – 150 | 20 |
| 150 – 155 | 30 |
| 155 – 160 | 38 |
| 160 – 165 | 24 |
| 165 – 170 | 16 |
| 170 – 175 | 12 |
| 175 – 180 | 8 |
Draw an ogive for the given distribution taking 2 cm = 5 cm of height on one axis and 2 cm = 20 students on the other axis. Using the graph, determine:
- The median height.
- The interquartile range.
- The number of students whose height is above 172 cm.
The following table gives the age of 50 student of a class. Find the arithmetic mean of their ages.
| Age-years | 16 – 18 | 18 – 20 | 20 – 22 | 22 – 24 | 24 – 26 |
| No. of students | 2 | 7 | 21 | 17 | 3 |
Q 11
Find the mean of all numbers from 7 to 17.
The mean of the following frequency distribution is 25.8 and the sum of all the frequencies is 50. Find x and y.
| Class | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 |
| Frequency | 7 | x | 15 | y | 10 |
Find the mode of the following:
20, 20, 30, 30, 30, 30, 35, 40, 40, 45, 45, 45, 50, 55, 60, 60, 60 ,65, 70, 70, 70
The mean of a certain number of observations is 32. Find the resulting mean, if the observation is decreased by 20%.
Find the mean of squares of first five whole numbers.
The weekly sale of motor bikes in a showroom for the past 14 weeks given below. 10, 6, 8, 3, 5, 6, 4, 7, 12, 13, 16, 10, 4, 7. Find the median of the data.
Find the median of the 10 observations 36, 33, 45, 28, 39, 45, 54, 23, 56, 25. If another observation 35 is added to the above data, what would be the new median?
