The time spent by a customer at a checkout counter has mean 4 minutes and standard deviation 2 minutes. a) What is the probability that the total time taken by a random sample of 50 customers is less than 180 minutes? b) Find the 30th percentile of the total time taken by 50 customers.

step-by-step explanation:

one of the most important purposes of surface treatment is to alter surface properties according to the requirement of specific applications. for example, hydrophobic coating has been utilized on windshield and eyeglasses. gold atom monolayer on substrate has become a popular surface bioconjugation strategy.  

step-by-step explanation:

if you want to separate 54 into 6 individual tiers then you need to divide if you want to separate 54 into 6 individual tiers then you need to divide 6 and 54.

if you divide 9 by 6 you will get 54.

- hope i .

40 i don’t know lololol