Suppose 8 books stacked on top of one another. Each book is 1 5/9 inches thick. How high is the stack of books?

Answer:

Part a:

The null and alternate hypotheses are

i) H0:  ud  ≥ u    vs          Ha: ud < u

ii) As the significance level is ∝= 0.025 and it is one tailed test then the critical region R < - 1.96

iii) The test statistics is  =−9.15

iv) We accept the alternate hypothesis.

​

Part b:   CI = (−3.637,−2.163)

​

Step-by-step explanation:

AS the sample sizes are sufficiently large (n1,n2> 30) we can use the sample standard deviations in place of population standard deviations.

Part a:

The null and alternate hypotheses are

i) H0:  ud  ≥ u    vs          Ha: ud < u

where

ud is the mean of the days missed  per year by mothers working for companies that provide day-care facilities on premises

and

u is the mean number of days missed per year by mothers working for companies that do not provide day-care facilities on premises

ii) As the significance level is ∝= 0.025 and it is one tailed test then the critical region R < - 1.96

iii) The test statistics is

z= xˉ1 − xˉ2/√ s 1² /n 1 +s 2² /n 2

​=  6.4−9.3/ √1.2 ² /45+ 1.85² /50​

=−9.15

iv) The calculated z = −9.15 values lies in the critical region= R < - 1.96 and the null hypothesis is rejected. Hence the  mean of absentees for companies that provide day-care facilities on premises  is less than the

the mean number of absentees for companies that do not provide day-care facilities on premises.

We accept the alternate hypothesis.

​

Part b:

The confidence interval can be calculated using the formula

CI = ( xˉ1 − xˉ2) ± z∝/2 √ s 1² /n 1 +s 2² /n 2

CI = (6.4−9.3) ± 2.326 * √1.2 ² /45+ 1.85² /50​

CI = (−3.637,−2.163)

​

Answer:

a = 6[tex]\sqrt{2}[/tex]

Step-by-step explanation:

[tex]a^{2}[/tex] + [tex]c^{2}[/tex] = [tex]18^{2}[/tex]    (pythagoras theorem)

[tex]a^{2}[/tex] + [tex]b^{2}[/tex] = [tex]4^{2}[/tex]      (pythagoras theorem)

[tex]c^{2}[/tex] + [tex]b^{2}[/tex] = [tex]22^{2}[/tex]      (pythagoras theorem)

From these 3 equations we can find the value of a

Answer:

theres a few ways to go about this...

ten j plus, four, plus eightj SIMPLIFY eighteen j's plus four

orrrr

2 times 5j+2 times2+2times4j and combine like terms to get the above expression

Answer:

3 dollars

Step-by-step explanation:

15 divided by 5 is 3

so 3 dollars each

hope this helps!

add me as a friend if you want:)

Answer:

(0,4)

Step-by-step explanation:

Answer:

It’s blurry but I think it’s an obtuse triangle

Step-by-step explanation:

Maybe a right triangle

Answer:

B) 20

The minimum of a data set is the smallest term of that set.

We arrange the terms in ascending order

→ 20,20,25,30,35

So, the minimum is 20

--------------------------------

hope it helps...

have a great day!!

Answer:

4

Step-by-step explanation:

Any polynomial of degree n has n roots

but we may need to use complex numbers

This is a 4th degree polynomial therefor:

4 roots

Answer:

(1,3)

Step-by-step explanation:

This might be wrong, sorry.

y+4x=7

I would think the pair is

(1,3)

Answer:

all the angles add up to 180 degrees

So 180÷6=30

(i got 6 cuz 1+2+3)

so 1=30

2=30*2=60

3=30*3=90

Answer:

Slope is -3

y-intercept is -3 and equation is y=-3x-3

Answer:

Slope: -3

y-intercept: -3

Equation: y = -3x - 3

Step-by-step explanation:

1. To get the slope (m):

m = rise / run = -3 / 1 --> it's negative 3 since the slope is going downwards

2. the y-intercept is the point that crosses the y-axis or when the x point is 0, so (0, -3)

3. Put is all together: y = -3x - 3

Answer:

Step-by-step explanation:

its 21.4

Answer:

The dimensions of the box that minimize the amount of material used is length of square base x = 70 cm and height of box = 35 cm

Step-by-step explanation:

The volume of the box with square base is V = x²h where x = length of side of square base and h = height of box.

Now, the area of the of box open at the top with dimensions of length, l , width, w and height, h are

A = 2lh + lw + 2wh

Now for a box of square base, l = w = x.

So, A = 2xh + x² + 2xh

A = x² + 4xh

Since V = x²h and V = 171500 cm³,

h = V/x² = 171500/x²

substituting h into A, we have

A =   x² + 4xh

A =  x² + 4x(171500 cm³/x²)

A =  x² + 4 × 171500 cm³/x

A =  x² + 686000 cm³/x

To find the value of x that minimizes A, we differentiate A with respect to x

So, dA/dx = d[x² + 686000 cm³/x]/dx

dA/dx = 2x - 686000 cm³/x²

equating this to zero, we have

2x - 686000 cm³/x² = 0

2x = 686000 cm³/x²

2x³ = 686000

x³ = 686000 cm³/2

x = ∛(343000 cm³)

x = 70 cm

To determine if this in a minimum dimension for A, we differentiate dA/dx and insert x = 70 cm

So, d²A/dx² = d[2x - 686000 cm³/x²]/dx

d²A/dx² = 2 + 3 × 686000 cm³/x³

d²A/dx² = 2 + 2058000 cm³/x³

with x = 70 cm, we have

d²A/dx² = 2 + 2058000 cm³/(70 cm)³

d²A/dx² = 2 + 2058000 cm³/343000 cm³

d²A/dx² = 2 + 6

d²A/dx² = 8 > 0

So, x = 70 is a minimum value for the dimension

Since h = 171500 cm³/x²

h = 171500 cm³/(70 cm)²

h = 171500 cm³/4900 cm²

h = 35 cm

So, the dimensions of the box that minimize the amount of material used is length of square base x = 70 cm and height of box = 35 cm

Answer:

4.2

Step-by-step explanation:

2.1+2.1=4.2

Answer:

4

Step-by-step explanation:

Since the bases are equal the powers also are equal

so

2x + 1 = x + 5

2x - x = 5 - 1

x = 4

Answer:

Option 2

Step-by-step explanation:

Like terms are terms with the same variable and the same power.

Let's analysis and write the equation of each model to see if which of them has like terms:

Option 1:

We have x x => 2x

1 1 1 => 3

Equation of model=> 2x + 3

2x and 3 are unlike terms

Option 2:

We have x x => 2x

x x x => 3x

Equation of model=> 2x + 3x

2x and 3x are like terms

Option 3:

We have x x x => 3x

1 1 1 => 3

Equation of model=> 3x + 3 (contains unlike terms)

Option 4:

We have x => x

1 => 1

Equation of model=> x + 1 (unlike terms)

✔️The second option is the answer

Answer:

∠APC ≅ ∠DPB angles adjacent to the same angle are congruent to each other.

Explanation:

Because they share an angle created by P, they are adjacent.

I hope this helped :)

Step-by-step explanation:

(5x⁴y⁵).(2x²y‐⁵)

5×2=10

x⁴×x²= x⁶

y⁵×y-⁵=y⁰

so the answer is 10x⁶y⁰

Answer:

x = 16

Step-by-step explanation:

The sum of the angles of a triangle are 180

128+ 2x-3 +23 = 180

Combine like terms

2x+148=180

Subtract 148 from each side

2x+148 -148 = 180-148

2x = 32

Divide by 2

2x/2 = 32/2

x =16

Answer:

11.

Step-by-step explanation:

As the first decimal place is 5 we round up the whole number.

Answer:

11

Step-by-step explanation:

See image below:)

Step-by-step explanation:

given,

m1=23°

m2=32°

hope it helps

Answer:

x = -6

Step-by-step explanation:

-x/3 = 2

Multiply each side by -3 to isolate x

-x/3  * -3= 2*-3

x = -6

Answer:

x= -6

Step-by-step explanation:

you want to issolate x.

Start by getting rid of that divison by inversing it. The inverse of division is multiplication, so we multiply 2 by 3 to get 6.

Now -x= 6

in order for it to be truely isolated, we must inverse the negative sign.

its x= -6

Answer:

x=00

Step-by-step explanation:l

nnm

Complete question:

The base of a pyramid covers an area of 14.0 acres (1 acre = 43, 560 ft²  ) and has a height of 481 ft. If the volume of a pyramid is given by the expression V = bh/3, where b is the area of the base and h is the height. If the height of the pyramid were increased to 512 ft and the height to base area ratio of the pyramid were kept constant, by what percentage would the volume of the pyramid increase

Answer:

The percentage increase of the volume is 6.45 %

Step-by-step explanation:

The volume of pyramid is calculated as;

V = bh/3

The initial volume of the pyramid is calculated as follows;

[tex]V = \frac{bh}{3} \\\\V_0 = (\frac{1}{3} ) \times (14 \ acres \ \times \frac{43,560 \ ft^2}{1 \ acre} ) \times (481 \ ft)\\\\V_0 = 97,777,680 \ ft^3[/tex]

The final volume of the pyramid when the height is increased to 512 ft.

[tex]V_1 = (\frac{1}{3} ) \times (14 \ acres \ \times \frac{43,560 \ ft^2}{1 \ acre} ) \times (512 \ ft)\\\\V_1 = 104,079,360 \ ft^3[/tex]

The percentage increase of the volume;

[tex]= \frac{104,079,360 - 97,777,680}{97,777,680} \times 100\%\\\\= 6.45 \ \%[/tex]

The volume of the pyramid will increase by 11.79%

The volume of a Pyramid is calculated using:

[tex]V = \frac{Bh}3[/tex]

Where:

When the height is increased from 458 to 512, then the initial and the final volumes are:

[tex]V_1 = \frac{458}{3}b[/tex]

[tex]V_2 = \frac{512}{3}b[/tex]

The percentage change is then calculated as:

[tex]\% Change = \frac{V_2 -V_1}{V_1} \times 100\%[/tex]

This gives

[tex]\% Change = \frac{512b/3 -458b/3}{458b/3} \times 100\%[/tex]

Simplify the numerator

[tex]\% Change = \frac{54b/3}{458b/3} \times 100\%[/tex]

Evaluate the quotient

[tex]\% Change = 0.1179 \times 100\%[/tex]

Express as percentage

[tex]\% Change = 11.79 \%[/tex]

Hence, the volume of the pyramid will increase by 11.79%

Read more about volumes at:

https://brainly.com/question/1972490

9514 1404 393

Answer:

  (-7, -6)

Step-by-step explanation:

The solution to the system of equations is the point that is on both lines: their point of intersection. That point is (-7, -6).

Answer:

-8 degrees Celsius is warmer

Answer:

-8 degrees C.

Step-by-step explanation:

The answer would be (3,2) because you would do (x,-y)