Question 5 - CBSE Class 10 Sample Paper for 2022 Boards - Maths Standard [Term 2] - Solutions of Sample Papers for Class 10 Boards

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Question 5 Mrs. Garg recorded the marks obtained by her students in the following table. She calculated the modal marks of the students of the class as 45. While printing the data, a blank was left. Find the missing frequency in the table given below Let Missing frequency be x Given Mode = 45 ∴ Modal class is 40 − 50 Mode = l + (𝒇𝟏 −𝒇𝟎)/(𝟐𝒇𝟏 − 𝒇𝟎 − 𝒇𝟐) × h where l = lower limit of modal class h = class-interval f1 = frequency of the modal class f0 = frequency of the class before modal class f2 = frequency of the class after modal class Now, Mode = l + (𝒇𝟏 −𝒇𝟎)/(𝟐𝒇𝟏 − 𝒇𝟎 − 𝒇𝟐) × h 45 = 40 + (𝑥 − 10)/(2𝑥 − 10 − 6) × 20 45 − 40 = (𝑥 − 10)/(2𝑥 −16) × 20 5 = (𝒙 − 𝟏𝟎)/(𝟐𝒙 −𝟏𝟔) × 20 5(2x − 16) = (x − 10) × 20 10x − 80 = 20x − 200 200 − 80 = 20x − 10x 120 = 10x 10x = 120 x = 120/10 x = 12 Hence, the missing frequency is 12