All categories

3 years ago

Eight values have a mean of 7. a ninth value is added. the new mean is 9. what is the new value

Mathematics

1 answer:

My name is Ann [436]3 years ago

4 0

Answer:

25 because the 8 values must times with 7 and will get 56. when the ninth value added , let the ninth value as y , 56+y , the new mean is 9 . so it will be like this , 56+y over 9 times with 9

You might be interested in

Identify which line from the graph the following right triangles could lie on.

qaws [65]

Answer:

Step-by-step explanation:

Slope of line A = $\frac{\text{Rise}}{\text{Run}}$

= $\frac{9}{3}$

= 3

Slope of line B = $\frac{9}{6}$

= $\frac{3}{2}$

Slope of line C = $\frac{6}{8}$

= $\frac{3}{4}$

5). Slope of the hypotenuse of the right triangle = $\frac{\text{Rise}}{\text{Run}}$

= $\frac{90}{120}$

= $\frac{3}{4}$

Since slopes of line C and the hypotenuse are same, right triangle may lie on line C.

6). Slope of the hypotenuse = $\frac{30}{10}$

= 3

Therefore, this triangle may lie on the line A.

7). Slope of hypotenuse = $\frac{18}{24}$

= $\frac{3}{4}$

Given triangle may lie on the line C.

8). Slope of hypotenuse = $\frac{21}{14}$

= $\frac{3}{2}$

Given triangle may lie on the line B.

9). Slope of hypotenuse = $\frac{36}{24}$

= $\frac{3}{2}$

Given triangle may lie on the line B.

10). Slope of hypotenuse = $\frac{48}{16}$

= 3

Given triangle may lie on the line A.

7 0

3 years ago

if one face of a cube has an area of 6.75 square inches , what is the surface area of the entire cube ?

Travka [436]

Answer:

40.5

Step-by-step explanation:

a cube has 6 faces so 6.75 x 6 = 40.5

3 0

3 years ago

On a coordinate grid, both point (−4, −1) and (2, 6) point are reflected across the y-axis. What are the coordinates of the refl

vichka [17]

The reflected points are (4, -1) and (-2, 6).

4 0

3 years ago

A dog walker charges a flat rate of $6 per walk plus an hourly rate of $30. How much does the dog walker charge for a 45 minute

zvonat [6]

Step 1

Find the equation in function notation

Let

h-------> the number of hours

y-------> the function for the walker fee in dollars

we know that

the hourly rate is $30\frac{\$}{hour}$

$y=6+30h$

in this linear equation

the independent variable is the variable h

the dependent variable is the variable y

Convert to function notation

Let

$f(h)=y$

$f(h)=6+30h$

Step 2

Find how much does the dog walker charge for a 45 minute walk

Convert the time in hours

$1\ hour=60\ minutes$

$45\ minutes=45/60=0.75\ hours$

substitute in the equation

For $h=0.75\ hours$

$f(0.75)=6+30*(0.75)=\$28.5$

therefore

the answer is

the dog walker charge for a 45 minute walk $\$28.5$

Statements

Step 3

The dependent variable is the number of hours true or false

The statement is false,

because the independent variable is the number of hours and the dependent variable is the walker fee in dollars

Step 4

The function for the walker fee is f(h)= 30h+6 true or false

The statement is True --------> see the Step 1

Step 5

The dog walker charges $22.5 for a 45 min walk true or false

The statement is False

Because the dog walker charges for a 45 minute walk $\$28.5$

5 0

3 years ago

According to the article "Fatigue Testing of Condoms" (Polymer Testing, 2009: 567–571), "tests currently used for condoms are su

daser333 [38]

Answer:

99% Confidence interval: (1196,1973)

Step-by-step explanation:

We are given the following in the question:

Sample size, n = 20

Mean, μ = 1584

Standard Deviation, σ = 607

99% Confidence interval:

$\bar{x} \pm t_{critical}\displaystyle\frac{s}{\sqrt{n}}$

Putting the values, we get,

$t_{critical}\text{ at degree of freedom 19 and}~\alpha_{0.01} = \pm 2.86$

$1584 \pm 2.86(\dfrac{607}{\sqrt{20}} )\\\\ = 1584 \pm 388.18\\ = (1195.82 ,1972.18)\\ \approx (1196,1973)$

Thus, there is a 99% chance that it will break in approximately 1196 to 1972

6 0

3 years ago