Question

Form the central difference table for the following data choosing x =35 as origin
x: 20 25 30 35 40 45
y: 12 15 20 27 39 52​

Answer 1

Step-by-step explanation:

Represent this data in the form of a frequency distribution table. Which is the most common, and which is the rarest, blood group among these student?

Sol. A, B, O, O, AB, O, A, O, B, A, O, B, A, O, O, A, AB, O, A, A, O, O, AB, B, A, O, B, A, B, O.

From the above table, we have:

The most common blood group is O.

The rarest blood group is AB.

2. The distance (in km) of 40 engineers from their residence to their place of work were found as follows:

Construct a grouped frequency distribution table with class size 5 for the data given above taking the first interval as 0 – 5 (5 not included). What main features do you observe from this tabular representation?

Sol. The given distance (in km) are:

Here, the observation with minimum and maximum value are 2 and 32 respectively.

∵ The first class interval is 0 – 5,

∴ The classes are: 0 – 5, 5 – 10, 10 – 15, 15 – 20, 20 – 25, 25 – 30, 30 – 35.

The required table is:

From the above table we observe that:

(i) Frequencies of class interval 5 – 10 and 10 – 15 are equal, i.e. 11 each. It shows that maximum number of engineers have their residences at 5 to 15 km away from their work place.

(ii) Frequencies of class intervals 25 – 30 and 25 – 30 are also equal, i.e. 1 each. It shows that minimum number of engineers have their residences at 20 to 30 km away from their work place.

3. The relative humidity (in %) of a certain city for a month of 30 days was as follows: