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2 years ago

The book was purchased for $8 and half of its price. How much does the book cost?

Mathematics

2 answers:

Step2247 [10]2 years ago

7 0

Answer: $16

Step-by-step explanation:

As the book was purchased for half its price plus 8 you can create the equation 1/2x + 8 = x. Then, simplifying the expression you get x = 16. Thus, the book costs 16 dollars.

Mekhanik [1.2K]2 years ago

6 0

Answer:

16$

Step-by-step explanation:

8*2=16

HOPE THIS HELPS :)

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The estimated daily living costs for an executive traveling to various major cities follow. The estimates include a single room

Alexandra [31]

Answer:

$\bar x = 260.1615$

$\sigma = 70.69$

The confidence interval of standard deviation is: $53.76$ to $103.25$

Step-by-step explanation:

Given

$n =20$

See attachment for the formatted data

Solving (a): The mean

This is calculated as:

$\bar x = \frac{\sum x}{n}$

So, we have:

$\bar x = \frac{242.87 +212.00 +260.93 +284.08 +194.19 +139.16 +260.76 +436.72 +355.36 +.....+250.61}{20}$

$\bar x = \frac{5203.23}{20}$

$\bar x = 260.1615$

$\bar x = 260.16$

Solving (b): The standard deviation

This is calculated as:

$\sigma = \sqrt{\frac{\sum(x - \bar x)^2}{n-1}}$

$\sigma = \sqrt{\frac{(242.87 - 260.1615)^2 +(212.00- 260.1615)^2+(260.93- 260.1615)^2+(284.08- 260.1615)^2+.....+(250.61- 260.1615)^2}{20 - 1}}$ $\sigma = \sqrt{\frac{94938.80}{19}}$

$\sigma = \sqrt{4996.78}$

$\sigma = 70.69$ --- approximated

Solving (c): 95% confidence interval of standard deviation

We have:

$c =0.95$

So:

$\alpha = 1 -c$

$\alpha = 1 -0.95$

$\alpha = 0.05$

Calculate the degree of freedom (df)

$df = n -1$

$df = 20 -1$

$df = 19$

Determine the critical value at row $df = 19$ and columns $\frac{\alpha}{2}$ and $1 -\frac{\alpha}{2}$

So, we have:

$X^2_{0.025} = 32.852$ ---- at $\frac{\alpha}{2}$

$X^2_{0.975} = 8.907$ --- at $1 -\frac{\alpha}{2}$

So, the confidence interval of the standard deviation is:

$\sigma * \sqrt{\frac{n - 1}{X^2_{\alpha/2} }$ to $\sigma * \sqrt{\frac{n - 1}{X^2_{1 -\alpha/2} }$

$70.69 * \sqrt{\frac{20 - 1}{32.852}$ to $70.69 * \sqrt{\frac{20 - 1}{8.907}$

$70.69 * \sqrt{\frac{19}{32.852}$ to $70.69 * \sqrt{\frac{19}{8.907}$

$53.76$ to $103.25$

8 0

2 years ago

F(x) = -3(x - 11)(x + 1)

il63 [147K]

Answer:

Step-by-step explanation:

8 0

3 years ago

Help needed

Alexeev081 [22]

The square root of a circle would be your answer because 4.2-8

5 0

2 years ago

PLEASE HELP ASAP!!!!!!!!!

viva [34]

Answer:

A: 5:1

B. 2:10

Step-by-step explanation:

Please mark brainliest!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

3 0

3 years ago

The human eye contains approximately 9.1 x 10^7 rod cells and 4.5 x 10^6 cone cells . Samuel subtracts 9.1-4.5 and says there ar

Paul [167]

Samuel is incorrect because he didn't subtract the power of the numbers.

<h3>How many more rod cells are there?</h3>

The number of rod and cone cells in the human eye is written in scientific notation. Scientific notation is used in expressing large numbers in smaller numbers. To write a number in scientific notation, the number is written as a decimal number, between 1 and 10 and multiplied by a power of 10. For example, 1 x 10² is equivalent to 100

(9.1 x 10^7) - (4.5 x 10^6)

= (9.1 - 4.5) x 10^(7 - 6)

4.6 x 10 = 46

To learn more about scientific notation, please check: brainly.com/question/25334755

#SPJ1

6 0

1 year ago