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3 years ago

Please help me with questions 8-13 I need help this is for a grade

Mathematics

1 answer:

sergiy2304 [10]3 years ago

6 0

For triangles, area is 1/2 base times height
8. Base 15 1/4 and height 18. Base and height can be flipped around to make the math easier, so 1/2(18)(15 1/4) = 9(15 1/4) = 9(61/4) = 549/4= 137 1/4 sq inches

9. Base 13 and height 11. Area = (1/2)(13)(11)= (13/2)(11) = 143/2 = 71 1/2 sq inches

10. Same thing again. Base = 30, height = 20, so area = (1/2)(30)(20) = 15(20) = 300 square km.

11. Base = 8, height = 5, so (1/2)(8)(5)= 4(5)= 20 square feet.

12. Base = 5, height = 3, so area = (1/2)(5)(3)= (5/2)(3)= 15/2; for 200 tiles we would take (15/2)(200)= 15(100) = 1500 square cm

13. Monica forgot to multiply base and height by 1/2.

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Assume that women's heights are normally distributed with a mean given by mu equals 62.5 in,and a standard deviation given by

Misha Larkins [42]

Answer:

(a) 0.5899

(b) 0.9166

Step-by-step explanation:

Let X be the random variable that represents the height of a woman. Then, X is normally distributed with

$\mu$ = 62.5 in

$\sigma$ = 2.2 in

the normal probability density function is given by

$f(x) = \frac{1}{\sqrt{2\pi}2.2}\exp{-\frac{(x-62.5)^{2}}{2(2.2)^{2}}}$ , then

(a) $P(X < 63) = \int\limits_{-\infty}^{63}f(x) dx$ = 0.5899

(in the R statistical programming language) pnorm(63, mean = 62.5, sd = 2.2)

(b) We are seeking $P(\bar{X} < 63)$ where n = 37. $\bar{X}$ is normally distributed with mean 62.5 in and standard deviation $2.2/\sqrt{37}$ . So, the probability density function is given by

$g(x) = \frac{1}{\sqrt{2\pi}\frac{2.2}{\sqrt{37}}}\exp{-\frac{(x-62.5)^{2}}{2(2.2/\sqrt{37})^{2}}}$ , and

$P(\bar{X} < 63) = \int\limits_{-\infty}^{63}g(x)dx$ = 0.9166

(in the R statistical programming language) pnorm(63, mean = 62.5, sd = 2.2/sqrt(37))

You can use a table from a book to find the probabilities or a programming language like the R statistical programming language.

4 0

3 years ago

What is 200x149 who can answer that for me i need help on this my teacher said i cant use couculater

ehidna [41]

Answer:

29,800

Step-by-step explanation:

that will be 149 x 2 which equals 298

149

×2 Multiply 9 × 2 = 18

------ Keep the 8 carry the 1 multiply 4 by 2 then add 1 finally multiply 2 by 1

298

Then add two zeros at the end since we're multiplying a number with two zeros. (This method only works for numbers that end with zeros)

Final answer: 29800

3 0

3 years ago

A local library claims it has 2.73x103 books. If there are 42 people in the building, how many books per capita are there?

Marizza181 [45]

Answer:

63 books per capita in the library

Step-by-step explanation:

Given

$Books = 2.73 * 10^3$

$People = 43$

Required

Determine the book per capita

To do this, we simply divide the number of books by number of person;

$Average = \frac{Books}{People}$

$Average = \frac{2.73 * 10^3}{43}$

$Average = \frac{2.73 * 1000}{43}$

$Average = \frac{2730}{43}$

$Average = 63.488372093$

$Average = 63$ (Approximated)

Hence;

<em>There are 63 books per capita in the library</em>

7 0

3 years ago

A bike store rents bikes for $9 an hour in addition to a helmet rental fee of $15. If

wel

Answer:

4 hours

Step-by-step explanation:

First we need to subtract the one pay fee (the helmet rental fee, $15)

So 51 - 15 = 36

Then we need to divide 36 by the amount of money it costs for each hours to find how many hours he rented the bike

So 39/9 = 4

3 0

2 years ago

John has $6 to buy school supplies. He buys 6 notebooks that are $0.52 each. He spends the remaining money buying erasers that a

Anuta_ua [19.1K]

John bought 18 erasers.

Explanation: He has $6.00

He spends $3.12 on notebooks
Then you do $6.00 - $3.12 and you get $2.88

If it’s ¢16 per eraser and he has no money left over after buying erasers than you would divide $2.88 by $0.16 which turns into 288 divided by 16 which comes out to 18.

Therefor John bought 18 erasers.

5 0

3 years ago