Mrs. Evans opens a bank account and starts to gain money at a constant rate of $3 per day. What is the total amount of money tha
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Here , two circles are given which are concentric. The radius of larger circle is 10cm and that of smaller circle is 4cm . And we need to find thelarea of shaded region.
From the figure it's clear that the area of shaded region will be the difference of areas of two circles.
Let the,
- Radius of smaller circle be r .
- Radius of smaller circle be r .
- Area of shaded region be
Answer:
The 80% confidence interval for the mean number of words a third grader can read per minute is between 40.4 wpm and 40.8 wpm.
Step-by-step explanation:
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 M as such
In which is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 40.6 - 0.2 = 40.4 words per minute.
The upper end of the interval is the sample mean added to M. So it is 40.6 + 0.2 = 40.8 words per minute.
The 80% confidence interval for the mean number of words a third grader can read per minute is between 40.4 wpm and 40.8 wpm.