The z score for a confidence level of 99% is 2.575.. You need to know this to complete this type of problem.. the other two commonly used confidence levels are 90% and 95% having z scores of 1.645 and 1.96 respectively. You need to memorize this!
To find the confidence interval, it will be defined as the sample mean plus/minus the margin of error.. Now to find the margin of error, divide the standard deviation of 12 by the square root of the number of elements in your sample(√250). Then take that result and multiply it by the Z score I mentioned above for a 99% confidence level.
In this case: the sample mean is 70 and the margin of error is approximately 1.95
So to calculate the confidence interval, do the following:
70 - 1.95 = 68.05 rounded to the nearest whole number is 68
70 + 1.95 = 71.95 rounded to the nearest whole number is 72
Looks like that would be the last choice. hope this helps.. it's been awhile since my work with statistics :-)
12w+15r=18.30 /*2
15w+10r=16.75 /*3
24w+30r=36.60, subtract this equation from the other one
45w+30r=50.25
21w=13.65
w=13.65/21
w=0.65 is a cost per pound for wheat flour
From the first equation we have
r=(18.30-12w)/15
r=(18.30-12*0.65)/15
r=0.70 is a cost per pound for rye flour
A cyclic quadrilateral is a quadrilateral inscribed in a circle
The measure of angle A is 106
<h3>How to determine the measure of angle A</h3>
From the question, we have:
<C= 74
Opposite angles of a cyclic quadrilateral add up to 180.
So, we have:
<A + <C = 180
This gives
<A + 74 =180
Subtract 74 from both sides
<A =106
Hence, the measure of angle A is 106
Read more about cyclic quadrilaterals at:
brainly.com/question/26168678
Answer:36pi or 113.0973355...
Step-by-step explanation:v=4/3pir^3 so 4/3pi*27 so 36pi or 113.0973355...
