The phrasing "nine times out of ten" means 9/10 = 0.90 = 90% is the confidence level. We're confident 90% of the time that the confidence interval captures the population parameter we're after (in this case mu = population mean)
The portion "have an average score within 5% of 75%" means that 75% = 0.75 is the center of the confidence interval, and it goes as low as 0.75 - 0.05 = 0.70 and as high as 0.75 + 0.05 = 0.80
This confidence interval is from 70% to 80%, meaning that nine times out of ten, we're confident that the average score is between 70% and 80%
We write the confidence interval as (0.70, 0.80). It's common to use the notation (L, U) to indicate the lower (L) and upper (U) boundaries. You might see the notation in the form L < mu < U. If so, then it would be 0.70 < mu < 0.80; either way they mean the same thing.
The margin of error is 0.05 as its the 5% radius of the interval. It tells us how far the most distant score is from the center (75%)
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In summary, we have these answers
- confidence level = 90%
- margin of error = 5% = 0.05
- confidence interval = (0.70, 0.80)
- interpretation = We're 90% confident that the average exam score is between 0.70 and 0.80
Answer: E. 150 square units.
Step-by-step explanation:A polygon is figure with at least 3 straight or definite sides or typically 5 or more straight sides.
Here the polygon we are given is a rectangle.
We know that,
Area of a rectangle = l x w
so we need to measure the length and width of the rectangle to find its area.
If we look closely, we can see the length of the rectangle above the x-axis is 8 units and the length below the x-axis 7 units which makes a total og 15 units.
(x - 5)^2 =
(x - 5)(x - 5) =
x^2 - 5x - 5x + 25 =
x^2 - 10x + 25 <===
Answer:
6.75
Step-by-step explanation:
Find the mean of the set {2,5,5,6,8,8,9,11} .
There are 8 numbers in the set. Add them all, and then divide by 8 .
2 + 5 + 5 + 6 + 8 + 8 + 9 + 118=548=6.75
