grouped data class intervals

There are three methods to find mean for a frequency distribution. (i) Direct method: where x is the mid-interval f is the frequency M is the mean (ii) Short-cut method: where A = assumed mean d = x - A (iii) Step-deviation method: where i = class size We illustrate eac..

The following data is about the grades of students in a test. Which of the following show the intervals of equal size to group the data? 58 73 80 79 51 66 67 59 60 73 76 76 78 78 60 57 78 62 65 => 51-65, 75-80 or 50-55, 55-60, 60-65, 65-70, 70-75, 75-80 or 51..

The formation of thioalcohols or thiols takes place when haloalkane is treated with-sodium or potassium hydrogen sulphide: the halogen atom gets replaced by hydrosulphide (-SH) group. ..

On treatment with mercaptide ion (RS - ) haloalkanes give thioethers. Thioethers are also formed by heating the haloalkanes with sodium or potassium sulphide. ..

Mrs.Smith has divided all the students in her class into groups. The line plot shows the number of girls in each group. Find the mode of the data shown. => 11 or 5 or 9 or 4..

Ionic radii increases down a group. Na + < K + < Rb + < Cs + F - < Cl - < Br - < I - This is because the number of shells increase. screening effect increases..

The tally chart represents the favorite colors of a group of students. Which graph represents the data correctly? => Graph 4 or Graph 2 or Graph 1 or Graph 3..

The stem and leaf plot shows the number of chocolates with the students of a class. How many data values are there in all in both the intervals 20 to 29 and 40 to 49? => 11 or 12 or 10 or 9..

Use the stem-and-leaf plot to find the number of data items in the interval 20 - 69. => 18 or 14 or 20 or 17..

Identify the incorrect statement(s). I. Percentiles divide the data set into 100 equal groups. II. Deciles divide the distribution into 10 equal groups. III. Quartiles divide the distribution into 25 equal groups. => all are incorrect or I only or II only or ..