Solve.The radioactive decay of radon 222 can be described by the equation A = Ce-0.1813t, where C is the original amount of radon and A is the amount of radon after t days. If 1.9 milligrams are in a laboratory container today, how much was there is the container 15 days ago? Round to the nearest hundredth.
A. 0.13 mg
B. 86.92 mg
C. 28.83 mg
D. 2.03 mg
Answer: C
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Use a graphing calculator to solve the system of equations. Round your solutions to one decimal place.2.6x - 2.1y + 2.7z = 2.03.2x - 7.0y - 1.7z = -4.64.4x + 1.1y + 2.3z = 3.6
A. (0.1, 0.4, 0.7) B. (0.1, 0.3, 0.5) C. (0.2, 0.5, 1.0) D. (0.0, 0.1, 0.2)
Find an equation that meets the given conditions.y varies directly as x2, and y = -200 when x = 10.
A. y = -2x2
B. y = -20x2
C. y = 2x2
D. y = 
Let x be a continuous random variable that is normally distributed, as indicated. Find the probability.standard normal distribution; Find P(0.7 ? x ? 1.4)
A. 0.242 B. 0.758 C. 0.9192 D. 0.1612
Find the missing values. Round amounts to the nearest dollar and rates to the nearest percent.Maturity value: 
Discount rate: 
Date made: 3/11Due date: 
Time: 90 daysDiscount: $223Proceeds: $9149
A. Maturity value: $9372 Discount rate: 8% Due date: 6/9 B. Maturity value: $9372 Discount rate: 10% Due date: 6/9 C. Maturity value: $9149 Discount rate: 10% Due date: 6/11 D. Maturity value: $9372 Discount rate: 10% Due date: 6/11