The quadratic equation is given by:
y = 3x² + 10x - 8
The standard equation of a parabola is given by:
y = ax² + bx + c
Where a, b, c are constants
At point (4, 80):
80 = a(4)² + b(4) + c
16a + 4b + c = 80 (1)
At point (-3, -11):
-11 = a(-3)² + b(-3) + c
9a - 3b + c = -11 (2)
At point (-1, -15):
-15 = a(-1)² + b(-1) + c
a - b + c = -15 (3)
Solving equations 1, 2 and 3 simultaneously gives:
a = 3, b = 10, c = -8
Therefore the quadratic equation becomes:
y = 3x² + 10x - 8
Find out more on quadratic equation at: brainly.com/question/1214333
Answer:
a) The formula is given by mean
the margin of error. Where the margin of error is the product between the critical value from the normal standard distribution at the confidence level selected and the standard deviation for the sample mean.
b)
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
If the distribution for X is normal or if the sample size is large enough we know that the distribution for the sample mean
is given by:
Part a
The formula is given by mean
the margin of error. Where the margin of error is the product between the critical value from the normal standard distribution at the confidence level selected and the standard deviation for the sample mean.
Part b
The confidence interval for the mean is given by the following formula:
UW is always equal to 9x-9 or 9(x-1) whenever x is a real number. By adding in x, we can get the value.
For example, if x was 4, we add in x, giving us 9*4-9=36-9=27 units or
9(4-1)=9(3)=27 units
Hoped this helped in time!