A bulb after certain testing had a life of 25 months. The standard deviation based on this sample of size one is

Step-by-step explanation:

Using the formula for calculating the standard error of the mean to get the standard deviation. The standard error of the mean is expressed as;

SE = S/√n where;

S is the standard deviation

n is the sample size

Given SE = 25 months and n = 1, on substituting this parameters into the formula, we will have;

25 = S/√1

25 = S/1

cross multiply

S = 25*1

S = 25 months

Hence the standard deviation based on the sample is 25 months

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.

a. 12.5 kg

step-by-step explanation:

f = ma

so

m = f/a = (2500 n)/(200 m/s²) = 12.5 kg

1 n = 1 kg·m/s²