Answer:
The mean for the second week is $2 less than the first and in percentage it is 22% less.
Step-by-step explanation:
The mean is given by the sum of all individual values divided by the number of values. For the first week the sum is:
sum1 = 6.5 + 8 + 7.25 + 13.5 + 9.75
sum1 = 45
Since she spent 10 less in the second week the sum is:
sum2 = sum1 - 10 = 45 - 10 = 35
The mean for each week is:
mean1 = sum1/5 = 45/5 = 9
mean2 = sum2/5 = 35/5 = 7
difference = mean1 - mean2 = 9-7 = 2
difference(%) = [2/9]*100 = 0.22*100 = 22%
The mean for the second week is $2 less than the first and in percentage it is 22% less.
Answer: 16
Step-by-step explanation:
multiplying by negative exponents can be a little tricky. So (1/4x)^-2 becomes 16/x^2 = __/x^2 so the missing number is 16
Answer:
a) 320 students
b) 25 students
Step-by-step explanation:
Number of 18-years old in the survey:
(We add all frequency points for each line)
0 + 30 + 20 + 60 + 70 + 40 + 60 + 40 + 0 = 320 students
Number of 18 year old spending between 25 and 35 minutes: 40 + 65 = 105
Number of 12 year old spending between 25 and 35 minutes: 30 + 50 = 80
105 - 80 = 25 students
Answer:
<h2>231cm²</h2>
Step-by-step explanation:
First, let's find the surface area of both the triangles
5x3=15
So, the surface area of the triangles is 15 sq.cm
Now, let's find the surface area of the base (large rectangle in the middle)
12x8=?
10x8=80
2x8=16
80+16=96
12x8=96
So, the surface area of the base, is 96sq.cm
Now, let's find the surface area of both of the side rectangles
12x5=60
60x2=120
So, the surface area of the two side rectangles is 120sq.cm
Now, let's find the total surface area by adding all of our answers.
120+96=216
216+15=231
<h2>
So hence, the surface area of this net is 231cm²</h2>
Answer:
V = (1/3)πr²h
Step-by-step explanation:
The volume of a cone is 1/3 the volume of a cylinder with the same radius and height.
Cylinder Volume = πr²h
Cone Volume = (1/3)πr²h
where r is the radius (of the base), and h is the height perpendicular to the circular base.
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<em>Comment on area and volume in general</em>
You will note the presence of the factor πr² in these formulas. This is the area of the circular base of the object. That is, the volume is the product of the area of the base and the height. In general terms, ...
V = Bh . . . . . for an object with congruent parallel "bases"
V = (1/3)Bh . . . . . for a pointed object with base area B.
This is the case for any cylinder or prism, even if the parallel bases are not aligned with each other. (That is, it works for oblique prisms, too.)
Note that the cone, a pointed version of a cylinder, has 1/3 the volume. This is true also of any pointed objects in which the horizontal dimensions are proportional to the vertical dimensions*. (That is, this formula (1/3Bh), works for any right- or oblique pyramid-like object.)
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* in this discussion, we have assumed the base is in a horizontal plane, and the height is measured vertically from that plane. Of course, any orientation is possible.
