The shop foreman has estimated that the proportion of time the machines in her department are idle is a mere 10%. on the basis of this estimate, a work sampling study is to be performed. (a) if we want a 95% confidence level that the true value of the proportion idle time is within ±2.5% of this 10% (that is, the confidence interval runs from 7.5% to 12.5%), how many observations must be taken? (b) suppose after the study is taken with the number of observations from part (a) the proportion of observations is actually 15% rather than 10%. what is the range of the 95% confidence interval in this case? (c) how many more observations need to be taken to achieve a confidence interval of 15% ±2.5%?

75

step-by-step explanation:

answer:   rotate 270° clockwise about (7, 1) and reflect across the line x = 7

step-by-step explanation:

because i took test

system of linear equation

step-by-step explanation:

as given in the data

a= 20 , b= -12

let us suppose that it is a straight line equation

now we know the formula for the system of linear equation

b= ma + c )

here m is slope of a straight line which is equal to formula

m=   (ii)

and here c is a constant

now putting the value of a and b in equation (ii)

m=

m=

putting the value of a,b and m in equation (i) gives us

-12 = + c

-12=-12 + c

adding 12 to both sides

-12 +12 = -12 +12 +c

0 =c

or c=0

as the value of the constant is zero which gives us that it is a linear equation and this order pair satisfies the system of linear equations.