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$(vi) Arithmetic mean is a measure that determines a value of the variable under study by dividing the sum of all values of the variable by their(a) number(b) group(c) denominator$  $(xxii) The positive square root of mean of the squared deviations of X_{i}(i=12 \ldots \ldots n) observations from their arithmetic mean is called(a) harmonic mean(b) range(c) standard deviation$  $(xv) The most frequent occurring observation in a data set is called(a) mode(b) median(c) harmonic mean$  $1. What do you understand by measures of central tendency?$  Example 2: Find the Range for the following distribution.\begin{tabular}{|c|c|}\hline Classes / Groups & \boldsymbol{f} \\\hline 10-19 & 10 \\\hline 20-29 & 7 \\\hline 30-39 & 9 \\\hline 40-49 & 6 \\\hline 50-59 & 7 \\\hline 60-69 & 1 \\\hline Total & 40 \\\hline\end{tabular}  now playing

$(vi) Arithmetic mean is a measure that determines a value of the variable under study by dividing the sum of all values of the variable by their(a) number(b) group(c) denominator$  $Example 2: A variable X takes the following values 45862 . Find the mean of X . Also find the mean when (a) 5 is added to each observation (b) 10 is multiplied with each observation (c) Prove sum of the deviation from mean is zero.$  