The front compound wall of a house is decorated by wooden spheres of diameter 21 cm, placed on small supports as shown in figure. Eight such spheres are used for this purpose, and are to be painted silver. Each support is a cylinder of radius 1.5 cm and height 7 cm and is to be painted black. Find the cost of paint required if silver paint costs 25 paise per cm2 and black paint costs 5 paise per cm2.
Find the mean of each of the following distributions :
(i)
xi |
10 |
15 |
20 |
25 |
30 |
35 |
40 |
Total |
fi |
4 |
6 |
8 |
18 |
6 |
5 |
3 |
50 |
(ii)
xi |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
Total |
fi |
1 |
3 |
4 |
8 |
10 |
3 |
1 |
30 |
(iii)
xi |
50 |
75 |
100 |
125 |
150 |
175 |
200 |
Total |
fi |
12 |
18 |
50 |
70 |
25 |
15 |
10 |
200 |
The following data have been overanged in ascending order. If the median of these data is 63, then find the value of x : 29, 32, 48, 50, x, x + 2, 72, 78, 84, 95
∵ Mean of 40 observations = 160
∴ Sum of 40 observations = 160 x 40 = 6400 Corrected sum of 40 observations
= 6400 - 125 + 165
= 6440
Correct mean =