The number of trials is n=6; the indexes of successful trials are k=0, 1, 2, 3; the probability of success for each single individual trial is p = 0.6). The formula to calculate the probability is P = P(0) + P(1) + P(2) + P(3) = P(n=6; k<=3; p=0.6) == . To facilitate my calculations, I used online calculator at this site https://stattrek.com/online-calculator/binomial.aspx It provides nice instructions and a convenient input and output for all relevant options/cases. The resulting number is P = 0.4557 (rounded). ANSWER
Hi Binomial Distribution: n=6, p=0.6 Using TI or similarly an inexpensive calculator like a Casio fx-115 ES plus P(X ≤ 3) = binomcdf(n, p, largest x-value) binomcdf(6, .6, 3) = .45568 0r .4557 Rounded to four decimal places. Agree with my distinguished colleague, recommend Using stattrek.com to check Results until You are familiar with Using Your Calculator. **Important to know what type of calculator may be used in a test situation.