Is its correct to say that in a histogram, the area of each rectangle is proportional to the class size of the corresponding class interval? If not, correct the statement

In a histogram, each class rectangle is constructed with base as

Is it correct to say that C.M. of a system of n-particles is always given by the average position vectors of the consituent particles? If not, when is this statement true?

Write the class size in each of the folowing 0-4,5-9,10-14

In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices. Assertion and reason both are correct statements and reason is correct explanation for assertion Assertion and reason both are correct statements but reason is not correct explanation for assertion. Assertion is correct statement but reason is wrong statement. Assertion is wrong statement but reason is correct statement. Assertion:Total numbr of octahedral voids present in unit cell of cubic close packing including the one that of present at the body centre is four Reason: Besides the body centre there is one octahedral void present a the centre of each of the six faces of the unit cell and each of the which is shared between two adjacent unit cells.

In these question, a statement of asertion followed by a statement of reason is given .Choose the correct answer out of the following choices: Assertion and reason both are correct statements and reason is correct explanation for assertion. Assertion and reason both are correct statements but reason is not correct explanation for assertion. Assertion is correct statement but reason is wrong statement. Assertion is wrong statement but reason is correct statement. Assertion:No interfernce pattern is observed,when two coherent source are infinetely close to each other. Reason:The fringe width is inversely proportional to the istance betwen the two slits.

In these question, a statement of assertion followed by a statement of reason is given .Choose the correct answer out of the following choices: Assertion and reason both are correct statements and reason is correct explanation for assertion. Assertion and reason both are correct statements but reason is not correct explanation for assertion. Assertion is correct statement but reason is wrong statement. Assertion is wrong statement but reason is correct statement. Assertion: The sun looks bigger in size at sunrise and sunset than during day. Reason: The phenomenon of diffraction bends light rays.

In these question, a statement of asertion followed by a statement of reason is given .Choose the correct answer out of the following choices: Assertion and reason both are correct statements and reason is correct explanation for assertion. Assertion and reason both are correct statements but reason is not correct explanation for assertion. Assertion is correct statement but reason is wrong statement. Assertion is wrong statement but reason is correct statement. Assertion:The electric vector is also called light vector. Reason:The elctric vector of an electromagnetic wave is responsible for its optical effect.

In these question, a statement of asertion followed by a statement of reason is given .Choose the correct answer out of the following choices: Assertion and reason both are correct statements and reason is correct explanation for assertion. Assertion and reason both are correct statements but reason is not correct explanation for assertion. Assertion is correct statement but reason is wrong statement. Assertion is wrong statement but reason is correct statement. Assertion:If a convex lens is kept in water,its convergent power decreses. Reason:Focal length of convex lens in water increases.