The answer would be d , because you have to add how many of each fish to equal up to the sum of 420 . which is x y . so the first equation is x + y = 420 . then it says he bought 6 times as many parrotfish as he did angelfish so you would have to multiply x which represents angelfish by 6 . to get the second equation of y = 6x .
Answer:
This statement can be made with a level of confidence of 97.72%.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 8.1 mm
Standard Deviation, σ = 0.5 mm
Sample size, n = 100
We are given that the distribution of thickness is a bell shaped distribution that is a normal distribution.
Formula:
Standard error due to sampling:

P(mean thickness is less than 8.2 mm)
P(x < 8.2)
Calculation the value from standard normal z table, we have,

This statement can be made with a level of confidence of 97.72%.
Gallons per day.......gallons / day.....so u put the gallons over the number of days, then divide
(1/2) / 6 = 1/2 * 1/6 = 1/12 of a gallon per day <==