Answer:
Step-by-step explanation:
120 x .6 =72
120-72 = 48
48x .6 = 28.8
72+28.8 = 100.8
She sold approximately 101 cups of coffee
Answer:
10
Step-by-step explanation:
the range is the difference between the biggest and the smallest number
55-45=10
Answer:
B, Work with the math instructors to create a list of students currently taking a math class. Randomly select
Step-by-step explanation:
Let's think of each scenario at a time.
(A) We select 100 students enrolled in college randomly that should be fine because we are taking only students that can take classes. this rules out faculty members and any other persons but also there may be students that will never take any math course as part of their study plan, this is ruled out on that basis.
(B)if we take 100 students from the list of math instructor, that will ensure that we have taken students that are taking math class now, and math is part of their study plan, seems fine.
(C) visiting cafeteria randomly on multiple days will give us random persons that may not even be enrolled in university. this can be ruled out on that basis.
(D)Ten class at random and surveying each student in every class will make sampling size large or small depending on students enrolled in each of the class this will not give us reliable results.
We can conclude that (B) is the beast method for obtaining reliable results.
The normal distribution curve for the problem is shown below
We need to standardise the value X=405.5 by using the formula


We now need to find the probability of z=0.32 by reading the z-table
Note that z-table would give the reading to the left of z-score, so if your aim is to work out the area to the right of a z-score, then you'd need to do:

from the z-table, the reading

gives 0.6255
hence,

The probability that the mean weight for a sample of 40 trout exceeds 405.5 gram is 0.3475 = 34.75%
If you're asking the difference between 14 ft and 21 ft your answer is 7 ft, just subtract 14 from 21