16.45 divided by 7 =2.35
2.35 multiply by 3=7.05
answer is 7.05
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 :-)
Answer:
x=-2
Step-by-step explanation:
<span>Consider the solid s described below. the base of s is the region enclosed by the parabola y = 5 - 5x2 and the x-axis. cross-sections perpendicular to the x-axis are isosceles triangles with height equal to the base. find the volume v of this solid.</span>
Interesting factoid: Only perfect squares have an odd number of factors. So we know to try 4, 9, and 16, and ignore the rest. It's 16, whose factors are 1, 2, 4, 8, and. 16 .
