# The Measurements (In Mm) of the Diameters of the Head of the Screws Are Given Below :Calculate the Mean Diameter of the Head of a Screw by the ' Assumed Mean Method'. - Algebra

Sum

The measurements (in mm) of the diameters of the head of the screws are given below :

 Diameter (in mm) no. of screws 33 - 35 9 36 - 38 21 39 - 41 30 42 - 44 22 45 - 47 18

Calculate the mean diameter of the head of a screw by the ' Assumed Mean Method'.

#### Solution

Let A = 40

 Diameter (in mm) Class Mark     (X) d =  X - A no. of screws f d 33 - 35 34 -6 9 -54 36 - 38 37 -3 21 -63 39 - 41 40 0 30 0 42 - 44 43 3 22 66 45 - 47 46 6 18 108 ∑ f =100 ∑fd = 57

bar"d" = (∑"f""d")/(∑ "f") = 57/100=0.57

Mean by Assumed Mean Method

bar"x" = "A" + bar"d"
=40 + 0.57
=  40.57  mm

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