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3 years ago

How many positive terms are in an arithmetic progression: 17.2; 17; 16.8

Mathematics

1 answer:

Fittoniya [83]3 years ago

7 0

Answer:

Step-by-step explanation:

a = first term = 17.2

tn = last term = 16.8

d= common difference = -0.2

n = number of terms = ?

To find the number of positive terms, we'll use the formula;

tn = a + (n - 1) d

Substituting the figures,

=> 16.8 = 17.2 + (n -1) -0.2

=> 16.8 - 17.2 = (n - 1) - 0.2

=> -0.4 = (n - 1) - 0.2

=> -0.4/-0.2 = n - 1

=> n - 1 = 2

=> n = 3

Therefore, the number of positive terms in the sequence is 3

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The American Management Association is studying the income of store managers in the retail industry. A random sample of 49 manag

VashaNatasha [74]

Answer:

a) The 95% confidence interval for the income of store managers in the retail industry is ($44,846, $45,994), having a margin of error of $574.

b) The interval mean that we are 95% sure that the true mean income of all store managers in the retail industry is between $44,846 and $45,994.

Step-by-step explanation:

Question a:

We have to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.95}{2} = 0.025$

Now, we have to find z in the Z-table as such z has a p-value of $1 - \alpha$ .

That is z with a p-value of $1 - 0.025 = 0.975$ , so Z = 1.96.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

$M = 1.96\frac{2050}{\sqrt{49}} = 574$

The lower end of the interval is the sample mean subtracted by M. So it is 45420 - 574 = $44,846.

The upper end of the interval is the sample mean added to M. So it is 45420 + 574 = $45,994.

The 95% confidence interval for the income of store managers in the retail industry is ($44,846, $45,994), having a margin of error of $574.

Question b:

The interval mean that we are 95% sure that the true mean income of all store managers in the retail industry is between $44,846 and $45,994.

5 0

3 years ago

A square pyramid is shown sitting on its base.

allochka39001 [22]

Answer:

Area of Pyramid = 384 cm²

Step-by-step explanation:

Given

Shape: Square Pyramid

Base: 12 cm

Height: 10 cm

Required

The Surface area.

The surface area of the pyramid is calculated by

1. Calculating the area of the base square

2. Calculating the area of the triangles

3. Adding (1) and (2) above

Having highlighted these points,

Step 1: First we calculate the area of the base square

The dimension of the square is 12cm x 12cm

Let L represent the length of the square (L = 12 cm)

So, Area = L * L

Area = 12 cm * 12 cm

Area = 144 cm²

Step 2: There are four triangles in the above pyramid (because the base is a square; and a square has four sides)

The dimension of each triangle is

Base: 12 cm

Height: 10 cm

First, we calculate the area of one triangle

Area = 0.5 * base * height

Area = 0.5 * 12 cm * 10 cm

Area = 60 cm²

If the area of 1 triangle is 60 cm², the area of 4 triangles would be

Area = 4 * 60 cm²

Area = 240 cm²

Step 3: Adding (1) and (2) above

Area of Pyramid = Area of base square + Area of triangles

Area of Pyramid = 144 cm² + 240 cm²

Area of Pyramid = 384 cm²

Hence, the surface area of the pyramid is 384 cm²

5 0

3 years ago

Jimmy's backyard is rectangle that is 18 5/6 yards long and 10 2/5 yards wide Jim buy sod in pieces that are 1 1/3 yard long and

g100num [7]

Answer:

111 pieces of soda

Step-by-step explanation:

step 1

Find the area of the rectangular backyard

The area of the rectangular backyard is equal to

$A=LW$

where

$L=18\frac{5}{6}\ yd=\frac{18*6+5}{6}=\frac{113}{6}\ yd$

$W=10\frac{2}{5}\ yd=\frac{10*5+2}{5}=\frac{52}{5}\ yd$

substitute

$A=(\frac{113}{6})(\frac{52}{5})$

$A=\frac{5,876}{30}\ yd^2$

step 2

Find the area of one piece of sod

The area of the rectangular piece of sod is

$A=LW$

where

$L=1\frac{1}{3}\ yd=\frac{1*3+1}{3}=\frac{4}{3}\ yd$

$W=1\frac{1}{3}\ yd=\frac{1*3+1}{3}=\frac{4}{3}\ yd$

substitute

$A=(\frac{4}{3})^2\\\\A=\frac{16}{9}\ yd^2$

step 3

Find the pieces of sod needed

To find out how many whole pieces of sod will Jim need to buy to cover his backyard, divide the area of the backyard by the area of one piece of soda

$\frac{5,876}{30} : \frac{16}{9}=\frac{52,884}{480}=110.175$

Round up

111 pieces of soda

8 0

3 years ago

Find the volume of a cone with a radius of 8 cm and height 15 cm? Round to the nearest tenth. Please show work.

Nonamiya [84]

You multiply radius by 3.14 by the height if you plug it in your equation is 8×3.14×15 which equals 1005.31 which rounds to 1005, the answer is 1005! :D

4 0

3 years ago

A line passes through the point (–6, –3) and has a slope of 2/3 . Which point is on the same line?

navik [9.2K]

Answer:

The point (0, 1) represents the y-intercept.

Hence, the y-intercept (0, 1) is on the same line.

Step-by-step explanation:

We know that the slope-intercept form of the line equation

y = mx+b

where

m is the slope

b is the y-intercept

Given

The point (-6, -3)

The slope m = 2/3

Using the point-slope form

$y-y_1=m\left(x-x_1\right)$

where

m is the slope of the line

(x₁, y₁) is the point

In our case:

m = 2/3

(x₁, y₁) = (-6, -3)

substituting the values m = 2/3 and the point (-6, -3) in the point-slope form

$y-y_1=m\left(x-x_1\right)$

$y-\left(-3\right)=\frac{2}{3}\left(x-\left(-6\right)\right)$

$y+3=\frac{2}{3}\left(x+6\right)$

Subtract 3 from both sides

$y+3-3=\frac{2}{3}\left(x+6\right)-3$

$y=\frac{2}{3}x+4-3$

$y=\frac{2}{3}x+1$

comparing with the slope-intercept form y=mx+b

Here the slope = m = 2/3

Y-intercept b = 1

We know that the value of y-intercept can be determined by setting x = 0, and determining the corresponding value of y.

Given the line

$y=\frac{2}{3}x+1$

at x = 0, y = 1

Thus, the point (0, 1) represents the y-intercept.

Hence, the y-intercept (0, 1) is on the same line.

5 0

3 years ago