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).
Answer:
C should be your answer if I'm not right then forgive me please.
Step-by-step explanation:
Answer:
-23
Step-by-step explanation:
you calculate 49-|6-14|x 9
you then calculate the absolute value
49-|-8|x 9
then multiply the numbers
49-8 x 9
calculate those numbers
49 - 72
your solution will be -23
Answer:
Step-by-step explanation:
4x = 60
60/4 = 15
width : 15
length: 45