Answer:
We need a sample size of at least 101
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 
.
So it is z with a pvalue of 
, so 
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.
What sample size is needed to estimate the true average speed to within 2 mph at 99% confidence?
We need a sample of at least n.
n is found when M = 2. So
Rounding up
We need a sample size of at least 101
Um A :)
hope this helps :)))))))))))))
3.3 is greater than 3.01
Hope this helps!
Answer:
He needs 5x+56 ft
Step-by-step explanation:
To find how much of fencing he needs , we find the perimeter of the given figure
All sides are equal in a square
To find perimeter of the square we add all the sides
4 sides we have for the square
one side is x, so perimeter of square = x+x+x+x= 4x
Now we find perimeter of rectangle
Opposite sides of rectangle are equal
Here for rectangle we consider only three sides
because fourth side is common for rectangle and square
So perimeter of the rectangle (with 3 sides) = 28 +x+ 28 = 56+x
Total fencing = perimeter of square + perimeter of rectangle
4x + 56 + x= 5x+56
4x-7=7x-61
-7=3x-61
54=3x
Answer
X=18
