Answer:
The minimum sample size needed is
. If n is a decimal number, it is rounded up to the next integer.
is the standard deviation of the population.
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 Z-table as such z has a p-value 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.
How large a sample must she select if she desires to be 90% confident that her estimate is within 4 ounces of the true mean?
A sample of n is needed, and n is found when M = 4. So






The minimum sample size needed is
. If n is a decimal number, it is rounded up to the next integer.
is the standard deviation of the population.
Using the formula V = L x W x H, multiply the 3 dimensions together.
17 x 1.3 x 8 = 176.8 cubic inches.
Length of x is 98.2 m
<u>Step-by-step explanation:</u>
Step 1:
Use the trigonometric ratio tan 27° to find the common side of both the right angled triangles.
tan 27° = opposite side/adjacent side = opposite side/9
∴ Opposite side = 9 tan 27° = 9 × - 3.27 = -29.46 m
Step 2:
Use this side and trigonometric ratio cosine to find the value of x.
cos 49° = adjacent side/x = -29.46/x
∴ x = -29.46/cos 49° = -29.46/0.30
= 98.2 m (negative value neglected)
Answer:
∠KJL = 45°
∠x=45°
∠DBC=67.47°
Step-by-step explanation:
x+x=90
2x=90
x=45°