1813 x

= 326.34
18% of 1813 people is 326.34 people
333 is a reasonable estimate.
You just have to arrange the equation such that the p is the only term at the left hand side of the equation. Express it in terms of r and m.
r = 1/2*m²*p
Divide both left and right hand side equations by 1/2*m²
p = r/(1/2 *m²)
Take the reciprocal of 1/2 and multiply it. The final answer is:
p = 2r/m²
the answer is 12.2 for 150 rounded to nearest tenth
a)
because it is equal to the area of the shaded region between X=4 and X=6, and the probability that X falls within some interval is given by the area under the PDF.
b)
because the shaded region is a rectangle of height 1/5 (by virtue of X following a uniform distribution over the interval [2, 7], which has length 5).
I think it’s 1.75 sorry if this is wrong