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3 years ago

I don’t understand can you help

Mathematics

1 answer:

Crazy boy [7]3 years ago

8 0

Answer:

A=6

Step-by-step explanation:

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Katt and sanjeev are collecting money for charity. For every £2 that kat collects, sanjeev collects £3. They collect £255 in tot

il63 [147K]

Answer: Kate = £102

Sanjeev = £153

Step-by-step explanation:

From the question, we are informed that for every £2 that kat collects, sanjeev collects £3. This csn be represented in a fraction as:

Kat = 2/5

Sanjeev = 3/5

The amount that each collects will be:

Kat = 2/5 × £255

= 2 × £51

= £102

Sanjeev = 3/5 × £255

= 3 × £51

= £153

6 0

3 years ago

A cellular phone company monitors monthly phone usage. The following data represent the monthly phone use of one particular cust

Fiesta28 [93]

SOLUTION

Given the question in the image, the following are the solution steps to answer the question.

STEP 1: Write the given set of values

$321,397,559,454,475,324,482,558,369,513,385,360,459,403,498,477,361,366,372,320$

STEP 2: Write the formula for calculating the Standard deviation of a set of numbers

$\begin{gathered} S\tan dard\text{ deviation=}\sqrt[]{\frac{\sum^{}_{}(x_i-\bar{x})^2}{n-1}} \\ where\text{ }x_i\text{ are data points,} \\ \bar{x}\text{ is the mean} \\ \text{n is the number of values in the data set} \end{gathered}$

STEP 3: Calculate the mean

$\begin{gathered} \bar{x}=\frac{\sum ^{}_{}x_i}{n} \\ \bar{x}=\frac{\sum ^{}_{}(321,397,559,454,475,324,482,558,369,513,385,360,459,403,498,477,361,366,372,320)}{20} \\ \bar{x}=\frac{8453}{20}=422.65 \end{gathered}$

STEP 4: Calculate the Standard deviation

$\begin{gathered} S\tan dard\text{ deviation=}\sqrt[]{\frac{\sum^{}_{}(x_i-\bar{x})^2}{n-1}} \\ \sum ^{}_{}(x_i-\bar{x})^2\Rightarrow\text{Sum of squares of differences} \\ \Rightarrow10332.7225+657.9225+18591.3225+982.8225+2740.52251+9731.8225+3522.4225+18319.6225+2878.3225 \\ +8163.1225+1417.5225+3925.0225+1321.3225+386.1225+5677.6225+2953.9225+3800.7225 \\ +3209.2225+2565.4225+10537.0225 \\ \text{Sum}\Rightarrow108974.0275 \\ \\ S\tan dard\text{ deviation}=\sqrt[]{\frac{111714.55}{20-1}}=\sqrt[]{\frac{111714.55}{19}} \\ \Rightarrow\sqrt[]{5879.713158}=76.67928767 \\ \\ S\tan dard\text{ deviation}\approx76.68 \end{gathered}$

Hence, the standard deviation of the given set of numbers is approximately 76.68 to 2 decimal places.

STEP 5: Calculate the First and third quartile

$\begin{gathered} \text{IQR}=Q_3-Q_1 \\ \\ To\text{ get }Q_1 \\ We\text{ first arrange the data in ascending order} \\ \mathrm{Arrange\: the\: terms\: in\: ascending\: order} \\ 320,\: 321,\: 324,\: 360,\: 361,\: 366,\: 369,\: 372,\: 385,\: 397,\: 403,\: 454,\: 459,\: 475,\: 477,\: 482,\: 498,\: 513,\: 558,\: 559 \\ Q_1=(\frac{n+1}{4})th \\ Q_1=(\frac{20+1}{4})th=\frac{21}{4}th=5.25th\Rightarrow\frac{361+366}{2}=\frac{727}{2}=363.5 \\ \\ To\text{ get }Q_3 \\ Q_3=(\frac{3(n+1)}{4})th=\frac{3\times21}{4}=\frac{63}{4}=15.75th\Rightarrow\frac{477+482}{2}=\frac{959}{2}=479.5 \end{gathered}$

STEP 6: Find the Interquartile Range

$\begin{gathered} IQR=Q_3-Q_1 \\ \text{IQR}=479.5-363.5 \\ \text{IQR}=116 \end{gathered}$

Hence, the interquartile range of the data is 116

3 0

1 year ago

Write the equation of the ellipse with foci at (-2,2) and (4,2) and major axis of length 10 *

Luda [366]

Answer:

The answer to your question is $\frac{(x - 1)^{2}}{25} + \frac{(y - 2)^{2}}{16} = 1$

Step-by-step explanation:

Data

Foci (-2, 2) (4, 2)

Major axis = 10

Process

1.- Plot the foci to determine if the ellipse is vertical or horizontal. See the picture below.

From the graph we conclude that it is a horizontal ellipse.

2.- Determine the foci axis (distance between the foci)

2c = 6

c = 6/2

c = 3

3.- Determine a

2a = 10

a = 10/2

a = 5

4.- Determine b using the Pythagorean theorem

a² = b² + c²

-Solve for b

b² = a² - c²

b² = 5² - 3²

b² = 25 - 9

b² = 16

b = 4

5.- Find the center (1, 2) From the graph, it is in the middle of the foci

6.- Find the equation of the ellipse

$\frac{(x - 1)^{2}}{5^{2}} + \frac{(y - 2)^{2}}{4^{2}} = 1$

$\frac{(x - 1)^{2}}{25} + \frac{(y - 2)^{2}}{16} = 1$

3 0

3 years ago

(a) Christine received 70 dollars.<br> Write a signed number to represent this change.

allochka39001 [22]

70 or +70
To represent a positive integer

8 0

2 years ago

I don't know how to do something

kotegsom [21]

Answer:what is the question ?

Step-by-step explanation:

4 0

3 years ago