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?]

Answers

Answer 1

Answer:

a) The probability that a randomly chosen specimen has an acceptable hardness is 0.7938.

b) If the acceptable range of hardness is (70-c, 70+c), then the value of c would 95% of all specimens have an acceptable hardness of 5.88.

c) Expected number of acceptable specimens among the ten is 7.938.

d) Binomial with n = 10 and p = P(X < 73.84)

[tex]p = P(Z <(73.84 - 70) / 3 ) = P(Z < 1.28) = 0.8997\\\\P(X <= 8) = 1 - P(X = 9) - P(X = 10)\\= 0.2650635[/tex]

Step-by-step explanation:

a )

[tex]P(67 < X< 75) = P( (67 - 70) / 3 < X < (75 - 70) / 3 )\\\\= P( - 1 < Z < 1.67) = 0.9525 - 0.1587 = 0.7938[/tex]

b )

[tex]c = 1.96 * 3 = 5.88[/tex]                    { Since Z = 1.96 for 95% CI refer table.}

c )

Expected number of acceptable specimens among the ten [tex]= 10 * P(67 < X< 75) \\\\= 10 * 0.7938 = 7.938[/tex]

d )

Binomial with n = 10 and p = P(X < 73.84)

[tex]p = P(Z <(73.84 - 70) / 3 ) = P(Z < 1.28) = 0.8997\\\\P(X <= 8) = 1 - P(X = 9) - P(X = 10)\\= 0.2650635[/tex]


Related Questions

A hybrid car was driven 300 mi and used 6 gal of gasoline. At the same rate of
consumption, how far would the hybrid car travel on 11.5 gal of gasoline?

Answers

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


Select the correct answer.
Which number has a repeating decimal form?
b.11/25
c.3/20
d.2/6

Answers

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.)

Multiply (5xy-4)(5xy+4)

Answers

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

Calculate 18t -t +69-6​

Answers

Answer:

17t + 63

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

You are riding your bike and notice the square sign above. You mentally draw a
straight line from point A to C. Describe the angle relationship between /_DCA and
/_BCA.

Answers

Answer: Both angles are equal to 45 degrees

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

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.

Which ordered pair (x,y) satisfies the inequality?

Answers

x because y because x because y because x

the picture
says it
all

Answers

Answer:

B. L BAT = L CAT

Step-by-step explanation:

__________

Decide if the following probability is classical, empirical, or subjective.

You guess that there is a 30% chance that you will be assigned homework in your English class on Tuesday

Answers

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.

if a binomial trial has a success of .3, how many successes would you expect out of 500 trails

Answers

Answer:

gfs

Step-by-step explanation:

Which of the following represents the factorization of the trinomial below?
-4x^2 - 4x^2 +24 x
ANSWER ASAP

Answers

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

NEED HELP ASAP

So for this problem I got 10.8 by multiplying 0.60 x 18. However it stated that my answer is incorrect. How do I go about this problem because I am not sure what else to do?

Answers

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).

What is the value of 6 / x + 2x squared when x = 3

Answers

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

2
3
4
9
10
-1
NS
-6
-7
-8
-9
Which three statements correctly describe key features of the function graphed here?

Answers

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

Multiply: 3x⎯⎯⎯⎯√·6y⎯⎯⎯⎯√
.

Answers

Answer:

l

Step-by-step explanation:

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. If a random sample of 400 new cars is selected. what is the probability that the proportion of new cars needing a warranty repair in the first 90 days will be: a. between 0.05 and 0.06? i.e. P(0.05 SpS 0.06) = (round your answer to 4 decimal places). b. above 0.07? i.e. P(p > 0.07) = (round your answer to 5 decimal places) c. below 0.03?ie. P(p < 0.03) = (round your answer to 4 decimal places)

Answers

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

Can someone answer with steps and explanation? Thanks.

Answers

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]

Select the correct answer from each drop-down menu.
Consider the function f(x) = 2x + 6 and the graph of the function g shown below.

The graph of g is the graph off translated (1,4,5 or 6) units (left, right, up, or down)
and g(x) =

Answers

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.

What are the transformation rules of a function?

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

which ordered pair is a solution to the system of inequalities graphed here?​

Answers

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


What is the slope of the line?
Pls help

Answers

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

find the GCF of 36 and 54

Answers

Answer:

Step-by-step explanation:

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

What is the slope of the line?
2x+ 4y = 6x- y

Answers

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

If p and q are the roots of 2x²+ 6x = 12 + 4x, and p < q, find q − p​

Answers

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]

pls I need an answer to this​

Answers

Answer:

10.20

the answer is in none of the options just choose

10.12

OPTION D is the correct answer

What is the equation line of A?
What is the equation line of B?

Answers

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

Question 7(Multiple Choice Worth 1 points)
(02.08 LC)
To follow appropriate safety procedures, what should soccer players wear?
Goggles
Helmets
Mouth pieces
Shin guards

Answers

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.

What are safety goggles?

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

State the domain of the graphed function, using interval notation. The domain is ______

Answers

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

HELP PLEASE QUICKKKKKK

Answers

Answer:

3

lkfbnrld/kgnvr/slkbvluydcfgiufhvgukrghoudgb

Factor completely 3x2 + 9x − 3.

3(x2 + 3)
3(x2 + 3x − 1)
3x(x2 + 3x − 1)
Prime

Answers

First factor or a 3
3(x^2+3x-1)
Answer=. 3(x2+3x-1)

i need help pls it’s timedd!!!!

Answers

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

Pedro and his friend Cody played basketball in the backyard. Cody made 5 Baskets . Pedro made 15 baskets. How many times more baskets did pedro make than cody?

Answers

Answer: 10

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

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