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 :-)
Step-by-step explanation:
Longest side is between 36 and 18 feet
18 < L < 36
IF longest side were 36 feet, width =0
IF longest side were 18, then width = 18
to be longest L>W L>18. and L can't be as much as 36 to keep width >0
You're very close. However, the less steep line should go through (4,7) and not some point slightly above that location. Also, the shaded region should be above both dashed lines at the same time. So you won't include the portion that I've marked in blue (see attached). Other than that, it looks great.
Answer:
6
Step-by-step explanation:
y=mx+b
93.40=8.40x+43
the 93 is the amount we want to get to, 8.40 represents the value of each sign and the 43 is the original cost
