Marco is selling floral arrangements. each arrangement uses 1 vase and 11 orchids. each vase costs marco $4.00. let c be the total cost of the arrangement and r be the cost of 1 orchid. which equation should marco use to find the total cost of each arrangement?
a) 11 = c +4r
b) 11c = r + 4
c) c = 4r + 1
d) c = 11r + 4

Which of the following is the correct equation for this function? a. y= (x+4)(x+2) b. y=x^2+ 3x – 2 c. y+ 2 = – 2(x+3)^2 d. y+ 2 = 2(x+3)^2

35 ! insert < , > , or = to make the sentence true. 12 __ 25 > =

Arandom sample of 15 observations is used to estimate the population mean. the sample mean and the standard deviation are calculated as 172 and 63, respectively. assume that the population is normally distributed. a. with 99 confidence, what is the margin of error for the estimation of the population mean? b. construct the 99% confidence interval for the population mean. c. construct the 95% confidence interval for the population mean. d. construct the 83% confidence interval for the population mean. hint: you need to use excel function =t. inv.2t to find the value of t for the interval calculation.