$136.00 should be split into 3 groups, for the 3 sisters. If you divide 136 dollars by 3, you would get 40. Jonathan should spend 40 dollars on each sister.
Given that the sample mean is μ=74 and sample standard deviation σₓ=
.
Thge Z- score is
.
Now we use the Z-score to calculate the required probability.
Refer to standard normal distribution table.
The required probability is

16 × (14 - 6) × 3 - 6^2 ÷ 6
parenthesis first
16 × (8) × 3 - 6^2 ÷ 6
exponents next
16 × (8) × 3 - 36 ÷ 6
multiplication and division from left to right
128 *3 -36 ÷ 6
384 -36 ÷ 6
384 -6
378
The coordinates of B would be (0,1)