Answer:
a) Mean = 600
Standard deviation = 12.24
B)No it is not likely because our probability of no pesticide is 75% which means that more than half of food items are without any pesticide
Explanation:
Total number of food items = 800
We are given that no pesticides were found at all in 75% of domestically produced food samples.
So, Probability of success = p = 0.75
Probability of failure = q = 1-p = 1-0.75=0.25
Now we are supposed to find
and
for random variable x
a) Mean = E(x)=

Standard deviation =

b)Is it likely that you would observe fewer than half of the food items without any traces of pesticides ? Why or why not ?
No it is not likely because our probability of no pesticide is 75% which means that more than half of food items are without any pesticide