The length of life of oil-drilling bits depends upon the types of rock and soil that the drill encounters, but it is estimated that the mean length of life is 55 hours. An oil exploration company purchases drill bits that have a length of life that is approximately normally distributed with mean equal to 55 hours and standard deviation equal to 9.1 hours.
What proportion of the company’s drill bits will have to be replaced after more than 90 hours of use?

Answers

Answer 1

Answer:

"0.9999" is the correct solution.

Step-by-step explanation:

The given values in the question are:

Mean,

= 55

Standard deviation,

= 9.1

Now,

⇒ [tex]z=\frac{X-mean}{sd}[/tex]

By putting the values, we get

⇒    [tex]=\frac{90-55}{9.1}[/tex]

⇒    [tex]=\frac{35}{9.1}[/tex]

⇒    [tex]=3.8461[/tex]

hence,

[tex]P(X<90)[/tex]

= [tex]P(Z<3.8461)[/tex]

= [tex]NORMSDIST(3.8461)[/tex]

then the value will be:

= [tex]0.9999[/tex]


Related Questions

According to the graph, the __________________ is 57-43.

Answers

Answer:

Range

Step-by-step explanation:

The range is the max value minus the min value

Find the area of lis triangle.
Round to the learest tenth.
8 m
62°
12 m
[?] m2

Answers

I think it’s 62 hope I’m right sorry if not

A figure with vertical line symmetry is placed on the coordinate plane. Given that the points (–8, –4) and (–3, –4) are on the edges of the figure, which of the following points lies on the line of symmetry?

Answers

Answer:

(-11/2; -4)

Step-by-step explanation:

The point that lies on the line is symmetry is the middle point of the segment

M(x) = (-8-3)/2 = -11/2

M(y) = -4

Answer:

(-11/2; -4)

Step-by-step explanation: The point that lies on the line is symmetry is the middle point of the segment

M(x) = (-8-3)/2 = -11/2

M(y) = -4

Find the area of the composite figure.
A. 65.1 sq in
B. 90.3 sq in
C. 106.3 sq in
D. 241.1 sq in

Answers

Answer:

I think B but not so sure

Hoping you have a good day

Answer:

Step-by-step explanation:

radius of semi circle=8/2=4 in

height of triangle=14-4=10 in.

area of composite figure=1/2×8×10+π×4²=40+16 π≈90.3 sq. in

A spinner is made of three equal sections blue green and red if I spend spend 180 times how many times I expect to get red as outcome

Answers

60 times

You have a 1/3 chance each spin.

1/3 = x/180
180 = 3x
x = 60

What is the volume of the cylinder below?

Use 3.14 for pi.

Answers

Answer:

V = 502.4 cm³

General Formulas and Concepts:

Symbols

π (pi) ≈ 3.14

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Geometry

Volume of a Cylinder Formula: V = πr²h

r is radiush is height

Step-by-step explanation:

Step 1: Define

r = 4 cm

h = 10 cm

Step 2: Find Volume

Substitute in variables [Volume of a Cylinder Formula]:                                V = (3.14)(4 cm)²(10 cm)Evaluate exponents:                                                                                         V = (3.14)(16 cm²)(10 cm)Multiply:                                                                                                             V = (50.24 cm²)(10 cm)Multiply:                                                                                                             V = 502.4 cm³

A. 1/3
B. 1
C. 2
D. 3/1
E. 1/2
F. 2/3

Answers

Answer:

B

Step-by-step explanation:

the graph is completely proportional so the answer would be 1

comments favorite math problem​

Answers

You want math problems???

Answer:

Hᴇʏᴀᴀᴀ!! ᴍʏ ɴᴀᴍᴇ ɪꜱ ᴘɪɴᴋʏ ᴀɴᴅ ɪ ᴀᴍ ʜᴇʀᴇ ᴛᴏ ᴀɴꜱᴡᴇʀ ʏᴏᴜʀ Qᴜᴇꜱᴛɪᴏɴ!!ʕ ꈍᴥꈍʔ☆

Step-by-step explanation:

ɪ ᴅᴏɴ'ᴛ ʀᴇᴀʟʟʏ ʟɪᴋᴇ ᴍᴀᴛʜ ʙᴜᴛ ɪꜰ ɪ ʜᴀᴅ ᴛᴏ ᴄʜᴏᴏꜱᴇ ᴀ ꜰᴀᴠᴏʀɪᴛᴇ ɪᴛ ᴡᴏᴜʟᴅ ʙᴇ ᴀʟɢᴇʙʀᴀ!!  (◕ᴗ◕✿)

  ʜᴀᴠᴇ ᴀɴ ᴀᴍᴀᴢɪɴɢ ɴɪɢʜᴛ ᴏʀ ᴅᴀʏ!

      *:・゚✧*:・゚ꜰʀᴏᴍ ʏᴏᴜʀ ᴏɴᴇ ᴀɴᴅ ᴏɴʟʏ ᴘɪɴᴋʏ  ʕ ゚ ● ゚ʔ✧✧・゚: *✧・゚:* *:・゚✧*:・゚

Which inequalities have the solution set graphed on the number line? Select two options. A number line going from negative 6 to positive 2. An open circle is at negative 4. Everything to the left of the line is shaded. x less-than negative 4 Negative 4 less-than x Negative 4 less-than-or-equal-to x Negative 4 greater-than x x greater-than negative 4

Answers

Answer:

[tex]x < -4[/tex]

[tex]-4 > x[/tex]

Step-by-step explanation:

Given

Description of number line

Range: -6 to 2

Open circle on -4

Left shaded

Required

Select the number line

From the question, we understand that the left side of the number line is shaded.

This means that the inequality is [tex]\le[/tex] or [tex]<[/tex]

Also, the open circle on -4 means that we discard [tex]\le[/tex].

So, the inequality is:

[tex]x < -4[/tex]

The opposite of the above inequality is:

[tex]-4 > x[/tex]

Answer:

A, D.  

Step-by-step explanation:

good luck with edge :)

Find the volume of the following cylinder in cubic inches

Answers

Answer:

Option (1)

Step-by-step explanation:

Volume of a cylinder is given by the formula,

V = πr²h

Here, V = Volume

r = Radius of the circular base

h = Height of the cylinder

From the picture attached,

r = 8 in.

h = 0.5 in.

By substituting these values in the formula,

V = π(8)²(0.5)

  = 32π

  = 32(3.14)

  = 100.48 in³

Therefore, Option (1) will be the correct option.

help please help please ​

Answers

Wouldn’t that be 2/3?! I may be wrong if so sorry

Evaluate 5x when x =8

Answers

Answer:

5x

= 5(8)

= 40

I hope I've helped

In a circle of radius 10 cm, a sector has an area of 40 (pi) sq. cm. What is the degree measure of the arc of the sector?
72
144
180°

Answers

Answer:

144°

Step-by-step explanation:

First, find the area of the circle, with the formula A = [tex]\pi[/tex]

Plug in 10 as the radius, and solve

A = [tex]\pi[/tex]r²

A = [tex]\pi[/tex](10²)

A = 100[tex]\pi[/tex]

Using this, create a proportion that relates the area of the sector to the degree measure of the arc.

Let x represent the degree measure of the arc of the sector:

[tex]\frac{40\pi }{100\pi }[/tex] = [tex]\frac{x}{360}[/tex]

Cross multiply and solve for x:

100[tex]\pi[/tex]x = 14400[tex]\pi[/tex]

x = 144

So, the degree measure of the sector arc is 144°

Answer:

Solution :-

We know that

Area = πr²

Area = 3.14 × (10)²

Area = 314/100 × 100

Area = 314 cm²

Now

40π/314 = x/360

40 × 3.14/314 = x/360

125.6/314 = x/360

0.4 = x/360

0.4 × 360 = x

144 = x

[tex] \\ [/tex]

Kari worked twice as many hours as Chris. She also worked ten less than three times as many hours as Mark. Chris and Mark worked the same number of hours.

Answers

Answer:

Kari = 20 hours

Chris = 10

Mark = 10

Explanation:

K is Kari's hours

C is Chris's hours

Karis = 2 x C = K

Chris = C

Mark = C

3C - 10 = K

Assume C is 10 (since 10 is 1/3 of the hours mentioned)

2 x 10 = 20 so K worked 20 hours

20 is twice as much as 10 (C's hours)

and it's 30 - 10 (10 less than 3 times as many hours as Mark)

Robert must read a few books from his home library. He read any 4 out of 6 books from the top shelf, and then any 2 out of 3 books from the middle shelf and then any 3 out of 6 books from the bottom shelf. In how many ways can Robert read the books, if different orders in which the books will be read count as different ways

Answers

Answer:

Robert can read the books in 129,600 different ways.

Step-by-step explanation:

The order in which the book are read is important, which means that the permutations formula is used to solve this question.

Permutations formula:

The number of possible permutations of x elements from a set of n elements is given by the following formula:

[tex]P_{(n,x)} = \frac{n!}{(n-x)!}[/tex]

Top shelf:

4 books from a set of 6. So

[tex]P_{(6,4)} = \frac{6!}{2!} = 360[/tex]

Middle shelf:

2 books from a set of 3. So

[tex]P_{(3,2)} = \frac{3!}{2!} = 3[/tex]

Bottom shelf:

3 books from a set of 6. So

[tex]P_{(6,3)} = \frac{6!}{3!} = 120[/tex]

Total:

360*3*120 = 129,600

Robert can read the books in 129,600 different ways.

kevin scored 11 points in his last basketball game. if kevin made two more free throws (one point each) then two-point shots, how many of each shot did he make? choose the graph that best depicts this problem.

Answers

Answer:

Kevin made 5 free throws and 3 two-point shots.

Step-by-step explanation:

Given that Kevin scored 11 points in his last basketball game, to determine if Kevin made two more free throws (one point each) than two-point shots how many of each shot did he make, the following calculation must be performed:

11 x 1 + 0 x 2 = 11

6 x 1 + 4 x 2 = 14

5 x 1 + 3 x 2 = 11

Therefore, Kevin made 5 free throws and 3 two-point shots.

Answer:

Step-by-step explanation:

Graph

HELP AND I WILL GIVE BRAINLIEST!
What is the value of c such that x^2 - 6x + c is a perfect-square trinomial?
a. 36
b. 9
c. -3
d. 18

Answers

Answer:

[tex]x^2 -6x +c \ is \ the \ perfect \ square\\=> x^2 -6x + c = (x -k)^2\\=>x^2 -6x+c = x^2 -2kx + k^2\\Equating \ the \ like \ terms,\\-6x = -2kx\\k = 3\\substituting \ k \ in \ (x-k) = (x-3)\\x^2 -6x +c = (x-3)^2\\\\X^2 - 6x + c = x^2 -6x +9 \\\\=> c = 9[/tex]

opion. b

Answer:

b

Step-by-step explanation:

Explain what the diameter of a circle is. If you had the diameter of a circle, how could you solve for the circumference?

Answers

Answer:

The diameter cannot solve for the circumference, you need the Radius to do it.

Step-by-step explanation:

If you want to use the Diameter divide the Diameter by 2. Diameter=D Radius=R

So to find the circumference of a Circle, 2÷D=R. Now we do 2[tex]\pi[/tex]R. So now to find the answer we have to do 2x[tex]\pi[/tex]xR


HELP

What is the equation of the trend line in the scatter plot ?

Answers

Yo bro I need food give six seven

(5x + 10) + (2x -3) =

Answers

Answer:

16

Step-by-step explanation:

I think sorry if I'm wrong

Answer: 7x+7

Step-by-step explanation:1

Eliminate redundant parentheses

(5x+10)+(2x-3)

(5x+10)+(2x−3)

5x+10+2x-3

5x+10+2x−3

2

Subtract the numbers

5x+10+2x−3

5x+7+2x

Combine like terms

5x+7+2x

 

7x+7

Solution

7x+7

(2)
3. Which of the following is NOT equal to 3/4
a.
a: (0)
b. 123
c. oo

Answers

The answer is b. 123

Answer:

hindi ko poaintindihan paayos po

One card is drawn from a regular deck of 52 cards. Find P (a red jack). Express your answer as a fraction and a percent, rounded to the nearest tenth of a percent.

Answers

Answer:

GIME SUM SKITTLES (Points)

Step-by-step explanation:

Answer:

Step-by-step explanation:

??.

Pls help me pls pls I am soo bad at math

Answers

Answer:

Length = 40

Height = 20

Step-by-step explanation:

If you multiply 40 x 20, it equals 800

20 is also half of 40 as well.

convert (-2,2) into equivalent polar coordinates

Answers

(2rad2, 135) is the polar equivalent

Explain why the data display is misleading and how it affects your perception of this data

PLZ HELP ILL GIVE BRAINLISEST IM DEPRTATE NDNAJD

Answers

Because for every items sold the difference is 1 and for 3-6 which has the most sold the difference is 3

1. Write an equation of the line in slope-intercept form that passes through (4.2) and (8.–2).

Answers

Answer:

its (8+4)/(-2-2) so the slope is -3x

Step-by-step explanation:

Plz help me well mark brainliest if correct....?.?.?.?

Answers

It’s 18 because it says perimeter meaning add all sides

Can someone please help me please....

Answers

Answer:

a

Step-by-step explanation:

A pair of dice was rolled many times
and the results appear below. Based
upon these results, what is the
experimental probability of rolling a 2?
Outcome
2
3
3
4
5
6
7
8
9
10
11
12
Frequency
3
6
00
11
14
16
15 12
9
5
1
The percent probability is = [ ? ]%
Round to the nearest percent.
Enter

Answers

I think that would be 16

What is the decimal equivalent of 2/3?

Answers

Answer:

0.66

Step-by-step explanation:

Answer:

i think 0.6

Step-by-step explanation:

i thank hope it helps

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