Advertisements
Advertisements
प्रश्न
A class consists of 50 students out of which 30 are girls. The mean of marks scored by girls in a test is 73 (out of 100) and that of boys is 71. Determine the mean score of the whole class.
उत्तर
Given, the number of girls out of 50 students = 30
∴ The number of boys out of 50 students = 50 – 30 = 20
Now, the marks obtained by 30 girls = 30 × 73 = 2190 and the marks obtained by 20 boys = 20 × 71 = 1420 ...[Mean of marks scored by girls in a test is 73 and that of boys is 71]
∴ Mean score of the whole class
= `("Marks obtained by 30 girls" + "Marks obtained by 20 girls")/("Number of girls" + "Number of boys")`
= `(2190 + 1420)/(20 + 30)`
= `3610/50`
= 72.2
Hence, the mean score of whole class is 72.2.
APPEARS IN
संबंधित प्रश्न
If the heights of 5 persons are 140 cm, 150 cm, 152 cm, 158 cm and 161 cm respectively,
find the mean height.
The mean of 200 items was 50. Later on, it was discovered that the two items were misread
as 92 and 8 instead of 192 and 88. Find the correct mean.
Find the missing value of p for the following distribution whose mean is 12.58.
| x | 5 | 8 | 10 | 12 | p | 20 | 25 |
| f | 2 | 5 | 8 | 22 | 7 | 4 | 2 |
Five coins were simultaneously tossed 1000 times and at each toss the number of heads wereobserved. The number of tosses during which 0, 1, 2, 3, 4 and 5 heads were obtained are shown in the table below. Find the mean number of heads per toss.
| No. of heads per toss | No.of tosses |
| 0 | 38 |
| 1 | 144 |
| 2 | 342 |
| 3 | 287 |
| 4 | 164 |
| 5 | 25 |
| TOtal | 1000 |
Find the median of the following data (1-8)
15, 6, 16, 8, 22, 21, 9, 18, 25
Find the mode of the following data :
7, 9, 12, 13, 7, 12, 15, 7, 12, 7, 25, 18, 7
Let m be the mid-point and l be the upper-class limit of a class in a continuous frequency distribution. The lower class limit of the class is ______.
If each observation of the data is increased by 5, then their mean ______.
The median of the data 78, 56, 22, 34, 45, 54, 39, 68, 54, 84 is ______.
Median of the following numbers: 4, 4, 5, 7, 6, 7, 7, 12, 3 is ______.
