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4 years ago

Explain how you could use 25% of a number to find the number.

Mathematics

1 answer:

katrin [286]4 years ago

6 0

Answer:

25% is the same as 1/4. So to find 25% of a quantity, divide it by 4. First find 10% of it. Then find 1% of it, and use that 1% to find 2% of it.

Step-by-step explanation:

You might be interested in

What is the quotient of 1 and 7 over 8 ÷ 3 over 8 ?

lakkis [162]

Answer:

⅐ ÷ 8 ÷ 3 / 8 = ³/₇

3 0

3 years ago

According to a flight statistics website, in 2009, a certain airline had the highest percentage of on-time flights in the air

sp2606 [1]

Answer:

a) 0.0139; b) 0.1809; c) 0.4278

Step-by-step explanation:

We use a normal approximation to a binomial distribution for these problems.

The sample size, n, for each is 30; p, the probability of success, is 0.808. This makes the mean, μ = np = 30(0.808) = 24.24. The standard deviation,

σ = √(npq) = √(30(0.808)(1-0.808)) = √(30(0.808)(0.192)) = √4.65408 = 2.1573

For part a,

We are asked for P(X < 20). Using continuity correction to account for the discrete variable, we find

P(X < 19.5)

z = (19.5-24.24)/(2.1573) = -4.74/2.1573 = -2.20

Using a z table, we see that the area under the curve to the left of this is 0.0139.

For part b,

We are asked for P(X = 24). Using continuity correction, we find

P(23.5 < X < 24.5)

z = (23.5-24.24)/2.1573 = -0.74/2.1573 = -0.34

z = (24.5-24.24)/2.1573 = 0.26/2.1573 = 0.12

Using a z table, we see that the area under the curve to the left of z = -0.34 is 0.3669. The area under the curve to the left of z = 0.12 is 0.5478. The area between them is then

0.5478-0.3669 = 0.1809.

For part c,

We are asked to find P(25 ≤ X ≤ 28). Using continuity correction, we find

P(24.5 < X < 28.5)

z = (24.5-24.24)/2.1573 = 0.26/2.1573 = 0.12

z = (28.5-24.24)/2.1573 = 4.26/2.1573 = 1.97

Using a z table, we see that the area under the curve to the left of z = 0.12 is 0.5478. The area under the curve to the left of z = 1.97 is 0.9756. The area between them is 0.9756 - 0.5478 = 0.4278.

4 0

4 years ago

a newly-planned tree needs to be staked with three wires. each wire is attached to the trunk 3ft. above the ground, and then anc

Alexandra [31]

| \
3ft | \
|_ _\
4ft
a²+b²=c² Pythagorean Theorem
3²+4²=c² simplify
c=√(3²+4²) isolate c
c=5

c*6=answer because you need wire for 6 trees
5*6=answer
answer=30

You will need 30 feet of wire

4 0

3 years ago

The width of a rectangle is one more than twice its length. If the rectangle's perimeter is 44 cm, then its length is ____ cm.

EleoNora [17]

Answer:

Part 1) The length is 7 cm

Part 2) The rate of return is r=11%

Step-by-step explanation:

Part 1)

Let

x ----> the length of rectangle

y ----> the width of rectangle