The Rockwell hardness of a metal is determined by impressing a hardened point into the surface of the metal and then measuring the depth of penetration of the point. Suppose the Rockwell hardness of a particular alloy is normally distributed with mean 70 and standard deviation 3. (Rockwell hardness is measured on a continuous scale.)a. If a specimen is acceptable only if its hardness is between 67 and 75, what is the probability that a randomly chosen specimen has an acceptable hardness?b. If the acceptable range of hardness is (70-c, 70+c) , for what value of c would 95% of all specimens have acceptable hardness?c. If the acceptable range is as in part (a) and the hardness of each of ten randomly selected specimens is independently determined, what is the expected number of acceptable specimens among the ten?d. What is the probability that at most eight of ten independently selected specimens have a hardness of less than73.84? [Hint: Y = the number among the ten specimens with hardness less than 73.84 is a binomial variable; what is p?]

Answer:

gfs

Step-by-step explanation:

Answer:

a) P(0.05 < p < 0.06) = 0.1332

b) P(p > 0.07) = 0.0011.

c) P(p < 0.03) = 0.1539

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Suppose that past records indicate that the probability that a new car will need a warranty repair in the first 90 days of use is 0.04.

This means that [tex]p = 0.04[/tex]

Sample of 400.

This means that [tex]n = 400, s = \sqrt{\frac{0.04*0.96}{400}} = 0.0098[/tex]

a. between 0.05 and 0.06?

This is the p-value of Z when X = 0.05 subtracted by the p-value of Z when X = 0.05. So

X = 0.06

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.06 - 0.04}{0.0098}[/tex]

[tex]Z = 2.04[/tex]

[tex]Z = 2.04[/tex] has a p-value of 0.9793.

X = 0.05

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.05 - 0.04}{0.0098}[/tex]

[tex]Z = 1.02[/tex]

[tex]Z = 1.02[/tex] has a p-value of 0.8461.

0.9793 - 0.8461 = 0.1332

So

P(0.05 < p < 0.06) = 0.1332

b. above 0.07?

This is 1 subtracted by the p-value of Z when X = 0.07. So

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.07 - 0.04}{0.0098}[/tex]

[tex]Z = 3.06[/tex]

[tex]Z = 3.06[/tex] has a p-value of 0.9989.

1 - 0.9989 = 0.0011. So

P(p > 0.07) = 0.0011.

c. below 0.03?

This is the p-value of Z when X = 0.03. So

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.03 - 0.04}{0.0098}[/tex]

[tex]Z = -1.02[/tex]

[tex]Z = -1.02[/tex] has a p-value of 0.1539. So

P(p < 0.03) = 0.1539

Answer:

3

lkfbnrld/kgnvr/slkbvluydcfgiufhvgukrghoudgb

Answer:

(x - 12)²

Step-by-step explanation:

Given

x² - 24x + 144

Required

Factorize

Start by expanding the expression

x² - 12x - 12x + 144.

Factorize.

x (x - 12) - 12(x - 12)

Factor out x - 12

(x 12)(x - 12)

Rewrite as

(x - 12)²

Answer:

[-10,-2) U (-2,2) U [2, 5) U (5, infinity)

Step-by-step explanation:

p/s: I don't have the infinity symbol on my keyboard but you know what it is. Hope this help

Answer:

Step-by-step explanation:

The greatest common factor of 36 and 54 is 18. 18×2=36 and 18×3=54.

Answer: 3

Step-by-step explanation:

Pick 2 coordinates that are on the line, for example, (-2,0) and (-1,3)

Slope = Rise/Run = (3-0)/(-1-(-2)) = 3

Answer: 10

Step-by-step explanation: 15 - 5 = 10

Answer:

Subjective.

Step-by-step explanation:

Classical probability:

A classical probability is a probability based on a formal reasoning, for example, probability of getting heads/tails on a coin toss.

Empirical probability:

An empirical probability is the same as experimental probability, that is, suppose 7 out of 10 people you meet are Buffalo Bills fans, so the next person has a 7/10 = 0.7 = 70% probability of being a Buffalo Bills fan.

Subjective probability:

Probability of somthing happening based on "intuition", that is, based on the person's own experience. In this exercise, we have an example of subjective probability.

did u add the attachment of the the statements? cuz i dont see it.

Step-by-step explanation:

The given equation can be further simplified into

[tex]2x^{2}+2x-12=0[/tex]

The roots of a quadratic equation is given by

[tex]x = \dfrac{ - b \: \pm \: \sqrt{ {b}^{2} - 4ac} }{2a} [/tex]

where a = 2, b = 2 and c = -12. Putting these into the roots equation, we get

[tex]x = \dfrac{ - 2 \: \pm \: \sqrt{4 \: - \: 4(2)( - 12)} }{2(2)} = \dfrac{ - 2 \: \pm \: 10}{4}[/tex]

This gives us two possible roots:

x = 2, x = -3

Since the condition is that p < q, we see that p = -3 and q = 2. Therefore,

[tex]q - p = 2 - ( - 3) = 5[/tex]

Answer:

8

Step-by-step explanation:

The equation will become 6/3+2(3)

-->6/3=2

-->Because of Order of Operation we will multiply the 2 and 3 before adding so 2(3) = 6

--> 6+2=8

Answer:

x=6

Step-by-step explanation:

when its squared you multiply by 2

Answer:

see below

Step-by-step explanation:

Line A is a horizontal line

It is of the form y = constant

y = 4

Line B is a vertical line

It is of the form x = constant

x = 8

===========================================================

Explanation:

When using the SSS congruence rule, we can prove that triangle DCA is congruent to triangle BCA.

Since the triangles are congruent, the corresponding pieces angle DCA and angle BCA are equal in measure (if they weren't, then the triangles wouldn't be congruent).

Recall that any square has four right angles, ie all angles are 90 degrees each. Angle DCB is cut in half to get 90/2 = 45.

The angles DCA and DCB are 45 degrees each.

We are looking for the total amount of the solution. We only know part of it, that there are 18 milliliters of the alcohol. We also know that the alcohol makes up only 60% of the solution.

To find the whole, we can set up a proportion using the information given.

60 / 100 <--- This is our percentage, which we were given.

18 / x <--- This is the part (alcohol - 60%) over the whole, which we don't know and which also corresponds to the 100.

Therefore, our proportion is as such:

60 / 100 = 18 / x

To solve, cross-multiply.

100 * 18 = 60 * x

1800 = 60x

x = 30 total milliliters of the solution

Hope this helps!

upandover has a great solution. Here's a slightly different approach.

x = total amount of solution (consisting of water and alcohol mixed)

0.60x = 60% of x = amount of pure alcohol

0.60x = 18 since we have 18 mL of pure alcohol

Divide both sides by 0.60 to isolate x

0.60x = 18

x = 18/0.60

x = 30

Answer:  30 mL of total solution (alcohol + water).

Answer:

[tex]x=-16\text{ or } x=7[/tex]

Step-by-step explanation:

Since ΔABC is mapped onto ΔDEF, we can write that:

[tex]\Delta ABC\cong \Delta DE F[/tex]

By CPCTC:

[tex]\angle A\cong \angle D[/tex]

And since ΔABC is isosceles with Vertex C:

[tex]\angle A \cong \angle B[/tex]

We are given that:

[tex]m\angle D=34[/tex]

Hence:

[tex]m\angle A=34=m\angle B[/tex]

We are also given that:

[tex]m\angle C=x^2+9x[/tex]

The interior angles of a triangle must sum to 180°. Thus:

[tex]m\angle A+m\angle B+m\angle C=180[/tex]

Substitute:

[tex](34)+(34)+(x^2+9x)=180[/tex]

Simplify:

[tex]68+x^2+9x=180[/tex]

Isolate the equation:

[tex]x^2+9x-112=0[/tex]

Factor:

[tex](x+16)(x-7)=0[/tex]

Zero Product Property:

[tex]x+16=0\text{ or } x-7=0[/tex]

Solve for each case:

[tex]x=-16\text{ or } x=7[/tex]

Testing the solutions, we can see that both yields C = 112°.

Hence, our solutions are:

[tex]x=-16\text{ or } x=7[/tex]

Step-by-step explanation:

-3,4 Is the answer Is it right or wrong if it is true plz mark me as brainliest

Answer:

Ano is correct

Step-by-step explanation:

-3,4is theoretically correct answer

Answer:

The answer is Mouth pieces

The piece of safety equipment that should be worn when painting a ceiling is safety goggles. The correct option is c.

Safety goggles are worn on the eyes. They are worn to get safety from sun, wind, and dust. If we work in a factory or some mechanical work, then goggles are must save eyes.

Here, we have,

When working with the ceiling, it has a chance to damage your eyes with the plaster and paint, so wearing safety goggles is necessary.

Thus, the correct option is c. safety goggles, in regard to being worn when painting a ceiling.

Learn more about safety goggles, here:

brainly.com/question/17225935

#SPJ2

Complete question:

Which of these pieces of safety equipment should be worn when painting a ceiling

a knee guards

b helmet

c safety goggles

d mouth guard

Answer:

Step-by-step explanation:

18t - t + 69 - 6

= 17t + 63 (Ans)

Answer:

17t + 63

Step-by-step explanation:

18t - t + 69 - 6

subtract we get

17 t + 63

[tex]{25x {}^{2} y}^{2} - 16[/tex]

Answer:

B. L BAT = L CAT

Step-by-step explanation:

__________

Answer:

575 miles

Step-by-step explanation:

Create a proportion where x is the distance traveled on 11.5 gallons of gas:

[tex]\frac{300}{6}[/tex] = [tex]\frac{x}{11.5}[/tex]

Cross multiply and solve for x:

6x = 11.5(300)

6x = 3450

x = 575

So, the car would travel 575 miles

Answer:

575 mi

Step-by-step explanation:

First we are going to find out how much gasoline the hybrid car uses per mile.

to do this we are going to divide 300 by 6.

[tex]\frac{300}{6}[/tex] = 50 mi

∴ For every 50 miles 1 gallon of gas is used. This can be represented as 1:50 or [tex]\frac{1}{50}[/tex].

To find the distance that 11.5 gallon of gas would be used we are going to multiply 50 by 11.5.

50 × 11.5 = 575 mi

Answer:

5.

Step-by-step explanation:

If you were to rotate the triangle, you can apply Pythagoras Theorem.

Therefore,

a^2 = 12^2 - 13^2 (Note: a^2 = a squared)

a^2 = 144 - 169

a^2 = -25.

a     = 5.

Not sure why its negative though im pretty sure its the right answer.

in BCD triangle :

DC^2 = BC^2 + BD^2

13^2 = 12^2 + BD^2

169 = 144 + BD^2

BD^2 = 169 - 144

BD^2 = 25

BD = 5

_______________________

In the other hand we have :

BD^2 = AB × BC

5^2 = AB × 12

AB = 25/12

________________________

Also we have :

AD^2 = AB × AC

AD^2 = 25/12 × ( 25/12 + 12 )

AD^2 = 25/12 × ( 25/12 + 144/12 )

AD^2 = 25/12 × 169/12

AD^2 = 25 × 169 / 12 × 12

AD^2 = 5 × 5 × 13 × 13 / 12 × 12

AD = 5 × 13 / 12

AD = 65 / 12

AD = 5.42

Thus the correct answer is option C

Answer:

4/5

Step-by-step explanation:

→ Rearrange to get into y = mx + c

5y = 4x + c

→ Divide everything by 5

y = 4/5x + c

Answer: The graph of g is the graph of f translated 5 units right, and g(x) = f(x - 5).

Step-by-step explanation:

The graph f(x) = 2x = 6 translated (1,4,5 or 6) units (left, right, up, or down) are g(x) = 2(x + 1) + 6, g(x) = 2(x - 4),  2x + 11, g(x) = 2x.

Suppose we have a function f(x).

f(x) ± d = Vertical upshift/downshift by d units (x, y ±d).

f(x ± c) = Horizontal left/right shift by c units (x - + c, y).

(a)f(x) = Vertical stretch for a > 0, vertical shrink a < 0. (x, ay).

f(bx) = Horizonatal compression b > 0, horizontal stretch for b < 0. (bx , y).

f(-x) = Reflection over y axis, (-x, y).

-f(x) = Reflection over x-axis, (x, -y).

Given, a function f(x) = 2x + 6.

g(x) is translated 1 units left.

g(x) = 2(x + 1) + 6.

g(x) is translated 4 units right.

g(x) = 2(x - 4).

g(x) is translated 5 units up.

g(x) = 2x + 6 + 5 = 2x + 11.

g(x) is translated 6 units down.

g(x) = 2x.

learn more about graphs here :

https://brainly.com/question/2288321

#SPJ2

Answer:

d.2/6 has a repeating decimal form

Answer:

[D. 2/6]

Step-by-step explanation:

For edmentum users (Please check your answers before placing the answer to avoid low grades and misconfusion.)

Answer:

l

Step-by-step explanation:

Answer:

10.20

the answer is in none of the options just choose

10.12

OPTION D is the correct answer