The 90% , 99% confidence interval for the population mean is 32.145 < 
< 35.855 and 31.093 < < 36.907
<h3>What is Probability ?</h3>
Probability is the study of likeliness of an event to happen.
It is given that
Total Population = 50
Mean = 35
The confidence interval is given by
is the mean
z is the confidence level value
s is the standard deviation
n is the population width
(a) The 90% confidence interval for the population mean
90% 
= 0.05
Z = 1.64
34 
1.64 * 8 / √50
34 1.855
32.145 < < 35.855
(b) The 99% confidence interval for the population mean
99% = 0.005
Z=2.57
34 2.57 * 8 / √50
34 2.907
31.093 < < 36.907
Therefore the confidence interval for population mean has been determined.
The complete question is
A simple random sample of 50 items from a population width =7 resulted in a sample mean of 35. If required, round your answers to two decimal places.
a. Provide a 90% confidence interval for the population mean
b. Provide a 99% confidence interval for the population mean
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SO SORRY I ANSWERED ON THE OTHER ONE! The answer is C. This line has a negative slope, and the ending number tells you the y-intercept.
Because the vertex of the parabola is at (16,0), its equation is of the formy = a(x-10)² + 15
The graph goes through (0,0), thereforea(0 - 10)² + 15 = 0100a = -15a = -0.15
The equation is y = f(x) = -0.15(x - 10)² + 15
The graph is shown below.
Part A
Note that y = f(x).
The x-intercepts identify values where the function or y=0. The x-intercepts occur at x=0 and x=20, or at (0,0) and (20,0).
The maximum value of y occurs at the vertex (10, 15) because the curve is down due to the negative leading coefficient of -0.15.
The curve increases in the interval x = (-∞, 10) and it decreases in the interval x = (10, ∞).
Part B
When x=12, y = -0.15(12 - 10)² + 15 = 14.4When x=15, y = -0.15(15 - 10)² + 15 = 11.25
The average rate of change between x =12 to x = 15 is(11.25 - 14.4)/(15 - 12) = -1.05
This rate of change represents the slope of the secant line from A to B. It approximates the rate at which f(x) decreases in the interval x =[12, 15].
Answer: 6,520 miles per year
Step-by-step explanation:
They had driven the car for 53,790 miles in 8.25 years.
The average number of number of miles driven per year is:
= 53,790 / 8.25 years
= 6,520 miles per year
<em>They drove an average of 6,520 miles per year.</em>
