Answer: 12 hours
Step-by-step explanation:
Given : Working together, it takes Sam, Jenna, and Francisco two hours to paint one room.
When Sam works alone, he can paint one room in 6 hours. When Jenna works alone, she can paint one room in 4 hours.
Let 't' be the time taken by Francisco to paint one room on his own.
Then , we have
Rate of work of Sam +Rate of work of Jenna + Rate of work of Francisco =Rate of work they all do together
i.e. 
i.e. 
i.e. 
i.e. 
i.e. 
i.e. 
i.e. t= 12
Hence, Francisco would take 12 hours to paint one room on his own.
The answer is letter d) 3
So average is of the first 6 tests is 82 well that means
(test1 + test2+ test3+ test4 + test5+test6)/6 = 82
so now let do some cross multiplliying
test1 + test2 + test3 + test 4 + test5 +test6 = 82*6
test1 + test2 + test3 + test 4 + test5 +test6 = 492
now lets see if we can find that 7th test score
(test1 + test2 + test3 + test4 + test5 +test6 + test7)/7 = 80.5
So look we found test1 + test2 + test3 + test4 + test5 +test6 to be 492 so lets substitute.
(492 + test7 )/7 = 80.5
test7 = (80.5*7)-492 = 71.5
Answer: .97
Step-by-step explanation:
Answer:
a) 18.4%
Step-by-step explanation:
Assuming a normal distribution, the z-score (z) for the probability of the average of the mosquitoes count being 'X' is given by:
Where 'μ' is the distribution mean, 'σ' is the standard deviation and 'n' is the number of square meters chosen.
For X = 81.8 and n=36:
A z-score of 0.9 is equivalent to the 81.59 th percentile in a normal distribution.
Therefore, the probability (P) that the average of those counts is more than 81.8 mosquitoes per square meter is:
