a) quadratic equation for P(t) is
P(t)= -0.051167 t2 + 4.08862 t-28.13953
b) when age is 23 , t=23 . apply t=23 and find P(t) to get this
P(23)=-0.051167 *232 + 4.08862*23-28.13953 = 38.831387
on rounding this it becomes 38.83
so 38.83 % of age 23 uses computer
c) this is a quadratic equation of the form f(x) =ax2+bx+c.
maximum of this function occur when a is negative and and occurs at
to find maximum find function value at this point.
for our function a= -0.051167 ,b=4.08862 . so maximum occur at
so age group at 39.95 uses maximum computer. it can be round to 40 . so age 40 uses maximum computer
find P(39.95) to get maximum percentage
P(39.95)=-0.051167 *39.952 + 4.08862*39.95-28.13953 = 53.53817
on rounding it becomes 53.54
so maximum percentage is 53.54
d) when halfe of workers use computer ,P(t) becomes 50 . apply P(t)=50 and solve
50=-0.051167 *t2 + 4.08862t-28.13953
on rearrainging
-0.051167 *t2 + 4.08862t- 78.13953=0
this is a quadratic equation of the form ax2+bx+c=0 .
solution for this is given by following quadratic formula
here a= -0.051167 ,b=4.08862 , c=-78.13953
apply to equation and find t
or
so for age 31.6 and 48.3 exactely 50% uses computer .
on rounding this becomes 48 and 32 ages
3) People who use computers at their job are listed in the table by ages. Age...