try dividing 2/3 by 1/2 idk if u can get any of those ansewrs
Answer:
pls explain better so make a mew question and take a picture
Answer:
A 90% confidence interval for the mean number of letter sounds identified in one minute is: (30.84, 37.34).
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
.
That is z with a pvalue of
, so Z = 1.645.
Now, find the margin of error 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 34.09 - 3.25 = 30.84.
The upper end of the interval is the sample mean added to M. So it is 34.09 + 3.25 = 37.34.
A 90% confidence interval for the mean number of letter sounds identified in one minute is: (30.84, 37.34).
The solution to the equation r(1 - 2cosФ) = 1 is given as x² + y² - 4x√(x² + y²) + 4x² = 1
<h3>What is an
equation?</h3>
An equation is an expression that shows the relationship between two or more variables and numbers.
In polar form:
r = √(x² + y²) and cosФ = x / √(x² + y²)
Hence:
r(1 - 2cosФ) = 1
√(x² + y²) [1 - 2(x / √(x² + y²))] = 1
√(x² + y²) - 2x = 1
Take square of both sides:
x² + y² - 4x√(x² + y²) + 4x² = 1
The solution to the equation r(1 - 2cosФ) = 1 is given as x² + y² - 4x√(x² + y²) + 4x² = 1
Find out more on equation at: brainly.com/question/2972832
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Hey.. don’t click on that link or any links on here !!! but i jus wanna say you didn’t attach an image of your question :).