A hint to get started
Translate left-handedness counts into binomial probabilities
In a particular large population, 15% of people are left-handed and the rest are right-handed. Twelve people are selected at random. Find the probability that (i) exactly 2 are left-handed, (ii) at most 3 are left-handed, (iii) more than 4 are left-handed, (iv) at least 7 are not left-handed, and (v) there are between 3 and 9 left-handed people.
CJC · Lecture · Example 2
Name X and state the four model conditions.
Use binompdf for equality and binomcdf for a lower cumulative probability.
Convert not-left-handed counts with 12−X and check the stated endpoint convention.