Answer:
0.5532
Step-by-step explanation:
P( 31<X<35.7)
P(X>31)= P(Z>(31-μ)/σ)
= P(Z>(31-34.6)/2.8)
= P(Z> -1.2857)
P(X<35.7)= P(Z<(35.7-μ)/σ)
= P(Z<(35.7-34.6)/2.8)
=P(Z< 0.392857)
From z-distribution table
P(Z< -1.29)= 0.09853
p(Z< 0.39) = 0.65173
P( 31<X<35.7)= P(Z<0.39)- P(Z<-1.29)
= 0.65173- 0.09853
=0.5532
3 years
ar(n)=total a is the first number which is 7000 r is the common ratio which is 100%+2%=102 102 divided by 100 giving u 1.02(interest) so ar(n)=sum n is written as power.....and is the number of years so 7000*1.02(n)=(7000+420) 1.02(n)=7420/7000 1.02(n)=1.06 log10 1.02(n)=log10(1.06) ( multiply log10 with both) n=log10(1.06)/log10 (1.02) u get 2.94 which is round off to 3 so 3 years.. hope This helps :)
The answer is 8.031 per person