Answer:
14.63% probability that a student scores between 82 and 90
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean 
and standard deviation 
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
What is the probability that a student scores between 82 and 90?
This is the pvalue of Z when X = 90 subtracted by the pvalue of Z when X = 82. So
X = 90
has a pvalue of 0.9649
X = 82
has a pvalue of 0.8186
0.9649 - 0.8186 = 0.1463
14.63% probability that a student scores between 82 and 90
It would be: 15/4 = 3 3/4
In short, Your Answer would be 3 3/4
Hope this helps!
Answer:
Radius of sphere is 3 units.
Step-by-step explanation:
Volume of sphere is given by 
surface area of sphere is given by 
where r is the radius of the sphere.
Given that
The number of cubic units in the volume of a sphere is equal to the number of square units in the surface area of the sphere.
we equate formula of Volume of sphere and surface area of sphere
assuming r as the radius.
thus,
Thus, radius of sphere is 3 units.
Answer:
45 feet
Step-by-step explanation:
To find the width of the model, we need to find the scale of the model to the actual tower.
Since we know the height of both towers, we can use that as the basis.
24 inches : 60 feet
12 inches : 30 feet
6 inches : 15 feet
So the width of the tower is 18 inches wide.
18 inches will then be equal to 12 + 7 inches : 30 + 15 feet
18 inches : 45 feet
Answer:
The jelly beans cost $2.25 / pound
The trail mix costs $1.25 / pound
Step-by-step explanation:
Let +a+ = cost/pound of jelly beans
Let +b+ = cost/pound of trail mix
(1) 6a + 2b =16
(2) 3a + 5b =13
Multiply both sides by 2
and subtract (1) from (2)
(2) 6a -2b = -16
(1) -6a -2b = -16
8b=10
b=1.25
and
(1) 6a+2b=16
(1) +3a+b=8
(1) 3a+1.25=8
(1) +3a=6.75
(1) a=2.25
