A series of elevations was determined The accidental error i

A series of elevations was determined. The accidental error in talking each reading is estimated to be + 0.005 ft. What is the total estimated error if 28 readings were taken?

_+ 0.14

_+ 0.374

_+ 0.026

_+ 1.97

10 points   

Solution

The answer to this problem is c

We know that the error propogates as the following in addition or substraction

E = sqrt ( E1^2 + E2^2 +E3^2 ........+ E28^2)

Here E1 ,E2 ,,,,, E28 all are equal to 0.005

Hence the net error will be

E = sqrt (28 * (0.005*0.005))

E = 0.0264