Suppose we are interested in analyzing the weights of NFL players. We know that on average, NFL players weigh 247 pounds with a
1 answer:
Answer:
a) The standard error would be of 8.58 pounds.
b) The margin of error is 14.11 pounds.
c) The 90% confidence interval for the population mean is between 232.89 pounds and 261.11 pounds
Step-by-step explanation:
a.What is the standard error?
The standard error is
In which is the standard deviation of the population and n is the size of the sample. So
The standard error would be of 8.58 pounds.
b.What is the margin of error at 90% confidence?
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
So it is z with a pvalue of , so
Now, find the margin of error M as such
The margin of error is 14.11 pounds.
c. Using my sample of 30, what would be the 90% confidence interval for the population mean?
Lower bound: Sample mean subtracted by the margin of error.
247 - 14.11 = 232.89 pounds
Upper bound
247 + 14.11 = 261.11 pounds
The 90% confidence interval for the population mean is between 232.89 pounds and 261.11 pounds
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The graph that matches the given equation is y≥x-1 is Graph A.
Option: C.
<u>Step-by-step explanation:</u>
The given equation y≥x-1 is a linear inequality equation.
Graphing Linear Inequalities differs from graphing regular linear equations. That is it has certain rules to be followed to draw the graph.
- First, rearrange the equation as y in the left and other terms in the opposite side.
- Check for the line: y= , y≤ and y≥ comes with straight line where as y< and y> comes with a dotted line.
- Shading: If y> greater than or y≥ greater than or equal is present then the space above the line has to be shaded. If y< less than or y≤ less than or equal is present then the space below the line has to be shaded.
For the given equation y≥x-1,
The line will be solid passing through (0,-1) and (3,2) since it has y≥. Also, the region above the line is shaded.
So the graph A is the graph that matches the equation y≥x-1.
The function
... y = 1/x
has derivative
... y' = -1/x²
which has no zeros. It is undefined at x=0, the only critical point. The derivative is negative for all values of x, so the function is decreasing everywhere in its domain.
Your function
... y = (x+1)/(x-3)
can be written as
... y = 1 +4/(x-3)
which is a version of y = 1/x that has been vertically scaled by a factor of 4, then shifted 1 unit up and 3 units to the right. Shifting the function to the right means x=3 is excluded from the domain (and the interval on which the function is decreasing).
The critical point is x=3.
The function is decreasing on (-∞, 3) ∪ (3, ∞), increasing nowhere.
