(b) A car manufacturer claims that its cars are capable of travelling 9 kilometres per litre of fuel. Test runs with 90 cars result in an average distance travelled per litre of fuel of only 8.2 kilometres, with a standard deviation of 2.5 kilometres. Carry out a one tailed test at the 5% level to test the manufacturers claim.​

y=mx+b is the final answer!   : )

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

the distance between the school and her home is 3.6km.

12 mins = 0.2 hours = 1/5 hour

54 ÷ 3 = 18km per hour

1/5 of 18 = 3.6km per 12 mins