Over a period of five days the average time on a computer train trip from one town to city was 77 minutes one trip was 71 minutes another trip was 74 minutes and two each were 78 minutes how many minutes long was the fifth trip



Answer :

84 minutes

1) Since we are dealing with the average then we need to plug all those 4 durations on this formula:

[tex]\begin{gathered} \bar{x}=\frac{71+74+78+78+t}{5} \\ 77=\frac{71+74+78+78+t}{5}(\times5) \\ 385=71+74+78+78+t \\ 385=301+t \\ 385-301=t \\ t=84 \end{gathered}[/tex]

Note that in the question there were two trips whose duration was 78 minutes.

2) Hene, the 5th trip was 84 minutes long