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2 years ago

Given 1 mile ≈ 1.6 kilometers, what is the standard deviation in kilometers? (enter your answer to two decimal places.)

1 answer:

3 0

You recorded the weekly distance you bicycled in miles and computed the standard deviation to be s= 3.1 miles. your friend wants to know the standard deviation in kilometers. Do you need to redo all the calculations?

No need to redo all the calculations. we use the given standard deviation. We convert the given standard deviation miles into kilometers.

Given 1 mile ≈ 1.6 kilometers

So 3 miles = 1.6 * 3.1 = 4.96 kilometers

standard deviation = 4.96 kilometers.

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"On a map, 0.25 inches represents 1 mile. What is the area of a rectangle on the map that is 3.75 inches long and 2.25 inches wi

Vika [28.1K]

0.25 inches represents 1 mile

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Find 1 inch:
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1 inch represents 1 ÷ 0.25 miles
1 inch represents 4 miles

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Find 3.75 inches:
----------------------------------------------
1 inch represents 4 miles
3.75 inches represent 4 x 3.75 miles
3.75 inches represent 15 miles

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Find 2.25 inches:
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1 inch represents 4 miles
2.25 inches represent 4 x 2.25 miles
2.25 inches represent 9 miles

----------------------------------------------
Find Area:
----------------------------------------------
Area = Length x Width
Area = 15 x 9
Area = 135 miles²

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Answer: 135 miles²
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6 0

2 years ago

Read 2 more answers

Which equation is y = 3(x – 2)2 – (x – 5)2 rewritten in vertex form? Y = 3 (x minus seven-halves) squared minus StartFraction 27

densk [106]

Answer: y = 2 (x minus one-half) squared minus StartFraction 27 Over 2 EndFraction

$y=2((x-\dfrac{1}{2})^2)-\dfrac{27}{2}$

Step-by-step explanation:

Vertex form of equation : $f (x) = a(x - h)^2 + k,$ where (h, k) is the vertex of the parabola.

$y=3(x-2)^2-(x-5)^2\\\\=3(x^2+4-4x)-(x^2+25-10x)\\\\=3x^2+12-12x-x^2-25+10x\\\\=2x^2-2x-13\\\\=2(x^2-x-\dfrac{13}{2})\\\\=2(x^2-x+\dfrac{1}{4}-\dfrac{1}{4}-\dfrac{13}{2})\\\\=2((x-\dfrac{1}{2})^2-\dfrac{1+26}{4})\\\\=2((x-\dfrac{1}{2})^2-\dfrac{27}{4})=2((x-\dfrac{1}{2})^2)-\dfrac{27}{2}$

Hence, the vertex form of the equation is $y=2((x-\dfrac{1}{2})^2)-\dfrac{27}{2}$

8 0

2 years ago

Read 2 more answers

At the parents evening the ratio of mums to dads was 3:2. Out of 500 appointments how many were with mums?

guajiro [1.7K]

Answer:

300

Step-by-step explanation:

Sum the parts of the ratio : 3 + 2 = 5 parts

Divide the number of appointments by 5 to find the value of one part of the ratio, that is

$\frac{500}{5}$ = 100 ← value of 1 part of the ratio

The mums consisted of 3 parts, hence

3 × 100 = 300 ← appointments with mums

3 0

2 years ago

Without actually writing the formula, explain how to expand (x + 3)7 using the binomial theorem.

dusya [7]

To write the coefficients of the 8 terms, either start with a combination of 7 things taken 0 at a time and continue to 7 things taken 7 at a time or use the 7th row of Pascal’s triangle.

For the first term, write x to the 7th power and 3 to the 0 power. Then decrease the power on x and increase the power on y until you reach x to the 0 and y to the 7.

Simplify by evaluating the coefficients and powers of 3.

8 0

2 years ago

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Write an expression involving integers for each statement a) moving 4 steps left, then moving 9 steps right b) on 3 separate occ

Charra [1.4K]

Answer:

a) x-4+9

b) x-2

For part b, I am not 100% sure about my answer, but I am sure about part a.

3 0

2 years ago