NCERT Class 10 Mathematics

256 MATHEMATICS Example 14 : An open metal bucket is in the shape of a frustum of a cone, mounted on a hollow cylindrical base m ...

SURFACE AREAS AND VOLUMES 257 Now, the volume of water that the bucket can hold (also, known as the capacity of the bucket) = () ...

258 MATHEMATICS EXERCISE 13.5 (Optional)* A copper wire, 3 mm in diameter, is wound about a cylinder whose length is 12 cm, and ...

SURFACE AREAS AND VOLUMES 259 Given a right circular cone, which is sliced through by a plane parallel to its base, when the sm ...

14 There are lies, damned lies and statistics. — by Disraeli 14.1 Introduction In Class IX, you have studied the classification ...

STATISTICS 261 x =^1 1 n ii i n i i fx f ✁ ✁ which, more briefly, is written as x = ✂ ✂ ii i fx f , if it is understood that i ...

262 MATHEMATICS Now, ✁ ii i fx x f = 1779 30 = 59.3 Therefore, the mean marks obtained is 59.3. In most of our real life situat ...

STATISTICS 263 Table 14.3 Class interval Number of students (fi) Class mark (xi) fixi 10 - 25 2 17.5 35.0 25 - 40 3 32.5 97.5 40 ...

264 MATHEMATICS The third step is to find the product of di with the corresponding fi, and take the sum of all the fi di’s. The ...

STATISTICS 265 Substituting the values of a, fidi and fi from Table 14.4, we get x = 47.5^435 47.5 14.5 62 30 ✁ ✂ ✁ ✂. Therefore ...

266 MATHEMATICS We have, ui = i x a h Therefore, u = () 1 i i ii i ii xa f fx a f h fhf ✁ ✂ ✄✂ ✁ ✂ ☎ ✆ ✝ ✞ ✂ ✟ ✂ ✠ = (^1) ii i ...

STATISTICS 267 Example 2 : The table below gives the percentage distribution of female teachers in the primary schools of rural ...

268 MATHEMATICS Table 14.7 Percentage of Number of xi di = xi – 50 = ^50 10 ui xi fixi fidi fiui female states/U.T. teachers (fi ...

STATISTICS 269 Example 3 : The distribution below shows the number of wickets taken by bowlers in one-day cricket matches. Find ...

270 MATHEMATICS Activity 2 : Divide the students of your class into three groups and ask each group to do one of the following a ...

STATISTICS 271 Thirty women were examined in a hospital by a doctor and the number of heart beats per minute were recorded and ...

272 MATHEMATICS A class teacher has the following absentee record of 40 students of a class for the whole term. Find the mean n ...

STATISTICS 273 Clearly, 2 is the number of wickets taken by the bowler in the maximum number (i.e., 3) of matches. So, the mode ...

274 MATHEMATICS Mode =^10 (^2) 10 2 ff lh ff f ✂ ✁ ✄✆ ✝☎ ✞ ✂ ✂ ✟ = 87 2 3 2 3 3.286 28 7 2 7 ✂ ✁ ✄✆ ✝☎ ✠ ✄ ✠ ✞ ☎ ✂ ✂ ✟ Therefo ...

STATISTICS 275 of the students. In the first situation, the mean is required and in the second situation, the mode is required. ...