Ask question

Ask question

All categories

3 years ago

14

It takes 81 bricks to place along the walkway of the house. If the bricks cost $.15 a piece. How much would the brick border cos

t?

1 answer:

zysi [14]3 years ago

8 0

81 x 15 = $1215 is the brick border cost.

You might be interested in

The University of Washington claims that it graduates 85% of its basketball players. An NCAA investigation about the graduation

Nonamiya [84]

Probabilities are used to determine the chances of events

The given parameters are:

Sample size: n = 20
Proportion: p = 85%

<h3>(a) What is the probability that 11 out of the 20 would graduate? </h3>

Using the binomial probability formula, we have:

$P(X = x) = ^nC_x p^x(1 - p)^{n -x}$

So, the equation becomes

$P(x = 11) = ^{20}C_{11} \times (85\%)^{11} \times (1 - 85\%)^{20 -11}$

This gives

$P(x = 11) = 167960 \times (0.85)^{11} \times 0.15^{9}$

$P(x = 11) = 0.0011$

Express as percentage

$P(x = 11) = 0.11\%$

Hence, the probability that 11 out of the 20 would graduate is 0.11%

<h3>(b) To what extent do you think the university’s claim is true?</h3>

The probability 0.11% is less than 50%.

Hence, the extent that the university’s claim is true is very low

<h3>(c) What is the probability that all 20 would graduate? </h3>

Using the binomial probability formula, we have:

$P(X = x) = ^nC_x p^x(1 - p)^{n -x}$

So, the equation becomes

$P(x = 20) = ^{20}C_{20} \times (85\%)^{20} \times (1 - 85\%)^{20 -20}$

This gives

$P(x = 20) = 1 \times (0.85)^{20} \times (0.15\%)^0$

$P(x = 20) = 0.0388$

Express as percentage

$P(x = 20) = 3.88\%$

Hence, the probability that all 20 would graduate is 3.88%

<h3>(d) The mean and the standard deviation</h3>

The mean is calculated as:

$\mu = np$

So, we have:

$\mu = 20 \times 85\%$

$\mu = 17$

The standard deviation is calculated as:

$\sigma = np(1 - p)$

So, we have:

$\sigma = 20 \times 85\% \times (1 - 85\%)$

$\sigma = 20 \times 0.85 \times 0.15$

$\sigma = 2.55$

Hence, the mean and the standard deviation are 17 and 2.55, respectively.

Read more about probabilities at:

brainly.com/question/15246027

8 0

2 years ago

There are 33 of them altogether and pay £311 in total. How many kids are in the family? Adults pay £15 and kids pay £7

Marrrta [24]

Answer:

Step-by-step explanation

Let x be the number of adults and y the number of kids

We can then write this two equations :

x+y= 33

15x+7y= 311

let's solve the two eaquations

to do that we should combine them both in a way that help us get rid of one of the variables.

Let's multiply the first equation by -7 to get rid of y by adding it to thr second equation

-7x-7y= -231

now add both equations .

15x+7y-7x-7y=311-231

we get : 8x = 80

as you notice y is gone and we get a classic easy equation to solve

x= 80/8

= 10

so the number of adults is 10

let's go back to the first equation ( x+y= 33) and replace x with 10

10+y= 33

y= 33-10

=23

let's check using the second equation :

(10*15)+(23*7) = 311

that is true

so :

the number of adults is 10
the number of kids is 23

4 0

3 years ago

After 3 years, Remington earned $390 in simple interest from a CD into which he initially deposited $4000. What was the annual i

olganol [36]

R=I/pt
R=(390÷(4,000×3))×100
R=3.25%

3 0

3 years ago

Read 2 more answers

Guillermo saved 25% of his paycheck last week. His paycheck was $1000. How much money did he save?

Bingel [31]

He saved 250 dollars.

8 0

3 years ago

Read 2 more answers

HELP!!! I NEED THIS DONE ASAP!

GarryVolchara [31]

20 and 7 Because 4x5 = 20

6 0

3 years ago

Read 2 more answers