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3 years ago

11

Today, the Great Pyramid at Giza near Cairo, Egypt stands 137 meters tall, coming to a point.Its base is a square with each side

measuring 230 meters wide. What is the slope of the pyramid?

1 answer:

Vlad1618 [11]3 years ago

8 0

Hope you can see the picture and understand the drawings.

It can seem complex at first but you just have to think it through.

I use pythagoras' theorem to find the diagonal of the base square and then use that information along with the height with the aid of that ever so handy pythagoras' theorem to find the length of the slope.

You might be interested in

In a process that manufactures bearings, 90% of the bearings meet a thickness specification. A shipment contains 500 bearings. A

Marina86 [1]

Answer:

(a) 0.94

(b) 0.20

(c) 90.53%

Step-by-step explanation:

From a population (Bernoulli population), 90% of the bearings meet a thickness specification, let $p_1$ be the probability that a bearing meets the specification.

So, $p_1=0.9$

Sample size, $n_1=500$ , is large.

Let X represent the number of acceptable bearing.

Convert this to a normal distribution,

Mean: $\mu_1=n_1p_1=500\times0.9=450$

Variance: $\sigma_1^2=n_1p_1(1-p_1)=500\times0.9\times0.1=45$

$\Rightarrow \sigma_1 =\sqrt{45}=6.71$

(a) A shipment is acceptable if at least 440 of the 500 bearings meet the specification.

So, $X\geq 440.$

Here, 440 is included, so, by using the continuity correction, take x=439.5 to compute z score for the normal distribution.

$z=\frac{x-\mu}{\sigma}=\frac{339.5-450}{6.71}=-1.56$ .

So, the probability that a given shipment is acceptable is

$P(z\geq-1.56)=\int_{-1.56}^{\infty}\frac{1}{\sqrt{2\pi}}e^{\frac{-z^2}{2}}=0.94062$

Hence, the probability that a given shipment is acceptable is 0.94.

(b) We have the probability of acceptability of one shipment 0.94, which is same for each shipment, so here the number of shipments is a Binomial population.

Denote the probability od acceptance of a shipment by $p_2$ .

$p_2=0.94$

The total number of shipment, i.e sample size, $n_2= 300$

Here, the sample size is sufficiently large to approximate it as a normal distribution, for which mean, $\mu_2$ , and variance, $\sigma_2^2$ .

Mean: $\mu_2=n_2p_2=300\times0.94=282$

Variance: $\sigma_2^2=n_2p_2(1-p_2)=300\times0.94(1-0.94)=16.92$

$\Rightarrow \sigma_2=\sqrt(16.92}=4.11$ .

In this case, X>285, so, by using the continuity correction, take x=285.5 to compute z score for the normal distribution.

$z=\frac{x-\mu}{\sigma}=\frac{285.5-282}{4.11}=0.85$ .

So, the probability that a given shipment is acceptable is

$P(z\geq0.85)=\int_{0.85}^{\infty}\frac{1}{\sqrt{2\pi}}e^{\frac{-z^2}{2}=0.1977$

Hence, the probability that a given shipment is acceptable is 0.20.

(c) For the acceptance of 99% shipment of in the total shipment of 300 (sample size).

The area right to the z-score=0.99

and the area left to the z-score is 1-0.99=0.001.

For this value, the value of z-score is -3.09 (from the z-score table)

Let, $\alpha$ be the required probability of acceptance of one shipment.

So,

$-3.09=\frac{285.5-300\alpha}{\sqrt{300 \alpha(1-\alpha)}}$

On solving

$\alpha= 0.977896$

Again, the probability of acceptance of one shipment, $\alpha$ , depends on the probability of meeting the thickness specification of one bearing.

For this case,

The area right to the z-score=0.97790

and the area left to the z-score is 1-0.97790=0.0221.

The value of z-score is -2.01 (from the z-score table)

Let $p$ be the probability that one bearing meets the specification. So

$-2.01=\frac{439.5-500 p}{\sqrt{500 p(1-p)}}$

On solving

$p=0.9053$

Hence, 90.53% of the bearings meet a thickness specification so that 99% of the shipments are acceptable.

8 0

3 years ago

Solve the system of equations. Write you answer as an ordered pair.

lawyer [7]

Answer:

x = -4 y = -5

Step-by-step explanation:

2x + 3 = -x - 9

3x + 3 = -9

3x = -12

x = -4

y = - (-4) - 9

y = 4 - 9

y = -5

6 0

2 years ago

Mr. and mrs. lorenzo want to buy a home valued at $213,500. if they have 18% of this amount saved for a down payment, how much h

Vesnalui [34]

Option d is the correct answer. $38,430.00 is the amount saved for a down payment given that Mr. and Mrs. Lorenzo want to buy a home valued at $213,500 and they have 18% of this amount saved for the down payment. This can be obtained by using percentage formula.

<h3>How much have they saved?</h3>

The percentage of a number can be obtained using percentage formula,

If P% of X is Y then it can be denoted using the formula of percentage as,

⇒ P% of X = Y

⇒ P% × X = Y (where P% is P/100)

Here in the question it is given that,

Mr. and Mrs. Lorenzo want to buy a home valued at $213,500

They have 18% of this amount saved for a down payment

We have to find the amount they saved for the down payment.

Given that the total amount = $213,500

Percentage they are saving = 18%

The amount they saved for the down payment,

18% of the total amount = 18% of $213,500

Using the percentage formula we get,

18% of $213,500 = 18% × $213,500

18% of $213,500 = 18/100 × $213,500

18% of $213,500 = $ 38,430.00

Hence Option d is the correct answer. $38,430.00 is the amount saved for a down payment given that Mr. and Mrs. Lorenzo want to buy a home valued at $213,500 and they have 18% of this amount saved for the down payment.

Learn more about percentages here:

brainly.com/question/14366896

#SPJ4

3 0

2 years ago

Greg and Erin start at the same point and begin running in different directions. Greg is running east at a speed of 7 miles per

AveGali [126]

Answer: The time at which the distance between the two is 150 miles is 1.3 hr.

Step-by-step explanation:

Step 1: Sketch the problem as shown in the attached image.

The problem can be solved using Pythagoras theorem since the sketch is a right angled triangle.

It follows the equation x² + y² = 15².

The distance covered by Greg is given by <em>x mi</em>, and that of Erin is given by <em>y mi</em>.

Step 2: To derive the distance covered by Erin and Greg, we use the formula <em>Speed = distance ÷ time.</em>

Which by cross-multiplying gives <em>distance = speed × time</em>.

Let time taken to cover the distance be <em>t h</em>.

Given that Speed of Erin is 9 mph and that of Greg is 7 mph.

Hence, distance covered by Greg, x = 7 × t = 7t.

Distance covered by Erin, y = 9 × t = 9t.

Step 3: Insert the terms x and y into the Pythagoras equation x² + y² = 15² and solve for <em>time t.</em>

(7t)² + (9t)² = 15²

49t² + 81t² = 225

(49 + 81)t² = 225

t² = 225/(49 + 81)

t² = 225/130

t² = 1.730769231

t = √1.730769231

t = 1.315587029

t = 1.3hr

Hence the time at which the distance between the two is 150 miles is 1.3 hr.

4 0

3 years ago

If (x^2−1)/(x+1) = 3x + 5, then x + 3 =<br> (A) -3<br> (B) -2<br> (C) 0<br> (D) 2<br> (E) 4

sineoko [7]

The answer is C) 0
Because math

4 0

2 years ago