In the same year, the average finishing time for u.s. women was four hours and 41 minutes. What was their average speed in miles
1 answer:
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Answer:
(3, 0)
Step-by-step explanation:
Given the inequality y > -2x + 3 and y ≤ x - 2
The graph of the inequalities are plotted using the geogebra graphing online calculator.
The portion of the graph that is shaded with dark blue, represents the portion that supports the equation.
All the ordered pair points given in the question are also labelled in the graph.
From the graph we can see that only point (3, 0) falls in the area that supports the equation. Hence (3, 0) makes both inequalities true.
Answer:
a) To determine the minimum sample size we need to use the formula shown in the picture 1.
E is the margin of error, which is the distance from the limits to the middle (the mean) of the confidence interval. This means that we have to divide the range of the interval by 2 to find this distance.
E = 0.5/2 = 0.25
Now we apply the formula
n = (1.645*0.80/0.25)^2 = 27.7 = 28
The minimum sample size would be 28.
b) To answer the question we are going to make a 90% confidence interval. The formula is:
(μ - E, μ + E)
μ is the mean which is 127. The formula for E is shown in the picture.
E = 0.80*1.645/√8 = 0.47
(126.5, 127.5)
This means that the true mean is going to be contained in this interval 90% of the time. This is why it doesn't seem possible that the population mean is exactly 128.
