PLEASE HEL

Identify the values of a, b, and c in the equation of the form y= ax to the power of 2 + bx + c below:

1.) y= 6x to the power of 2 - 4x + 3

2.) y= -x to the power of 2 - 5x

3.) y= 0.01x to the power of 2 - 0.5x + 1.8

4.) y= -12x to the power of 2 - 8x- 6

first, we define the variables:

x: number of years after 1950

f (x): amount of vinyl sold.

then, with the variables defined, we have:

68594 vinyl records were sold in 1958 > f (8) = 68594

91299 vinyl records were sold in 1961 > f (11) = 91299

38720 vinyl records were sold in 1952 > f (2) = 38720

161743 vinyl records were sold in 1967 > f (17) = 161743

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step-by-step explanation:

irst, find the z score of a score of 80. this is given by the formula z = (x-u)/o, where x is the score, u is the mean, and o is the standard deviation. this gives

z = (80-78)/12 = 1/6 = .1667

now, find what percentile a z score of 1/6 correlates to in the normal distribution.

a z score of 1/6 = .1667 is equivalent to the 56.36th percentile of the distribution. so the probability a score is over this is 1-.5636 = .4364

the mean of a sample mean is equal to the original mean. however, the standard deviation of a sample mean is equal to the original standard deviation divided by the square root of n (sample size). so the new standard deviation is 12/sqrt(16) = 3.

the new z score is 80-78/3 = 2/3 = .667. this is equivalent to the 74.86th percentile. so the probability that the mean will be greater than this score is 1-.7486 = .2514.

f(x) is   are being squared

g(x) is   increasing by 2

h(x) is adding .25 each time

k(x) is taking the square root

f(x) and k(x) are exponential functions