Answer:
[tex]Mean = 53.25[/tex]
Step-by-step explanation:
Given
Low Temperature : 40−44 || 45−49 || 50−54 || 55−59 || 60−64
Frequency: --------------- 3 -----------6----------- 1-----------3--- -----7
Required
Determine the mean
The first step is to determine the midpoints of the given temperatures
40 - 44:
[tex]Midpoint = \frac{40+44}{2}[/tex]
[tex]Midpoint = \frac{84}{2}[/tex]
[tex]Midpoint = 42[/tex]
45 - 49
[tex]Midpoint = \frac{45+49}{2}[/tex]
[tex]Midpoint = \frac{94}{2}[/tex]
[tex]Midpoint = 47[/tex]
50 - 54:
[tex]Midpoint = \frac{50+54}{2}[/tex]
[tex]Midpoint = \frac{104}{2}[/tex]
[tex]Midpoint = 52[/tex]
55- 59
[tex]Midpoint = \frac{55+59}{2}[/tex]
[tex]Midpoint = \frac{114}{2}[/tex]
[tex]Midpoint = 57[/tex]
60 - 64:
[tex]Midpoint = \frac{60+64}{2}[/tex]
[tex]Midpoint = \frac{124}{2}[/tex]
[tex]Midpoint = 62[/tex]
So, the new frequency table is as thus:
Low Temperature : 42 || 47 || 52 || 57 || 62
Frequency: ----------- 3 --||- -6-||- 1-||- --3- ||--7
Next, is to calculate mean by
[tex]Mean = \frac{\sum fx}{\sum x}[/tex]
[tex]Mean = \frac{42 * 3 + 47 * 6 + 52 * 1 + 57 * 3 + 62 * 7}{3+6+1+3+7}[/tex]
[tex]Mean = \frac{1065}{20}[/tex]
[tex]Mean = 53.25[/tex]
The computed mean is greater than the actual mean
Please answer this correctly without making mistakes
Answer:
2 13/15 miles
Step-by-step explanation:
Hey there!
Well first we need to find the distance between Lancaster and Hillsdale and Lancaster to Silvergrove.
9 + 7 13/15
= 16 13/15
LS is just 14 miles.
Now we can do,
16 13/15 - 14
= 2 13/15 miles
Hope this helps :)
Solve and graph the inequality. 45x + 5 < −3
Answer:
x < -8/45
Step-by-step explanation:
Step 1: Write out inequality
45x + 5 < -3
Step 2: Subtract both sides by 5
45x + 5 - 5 < -3 - 5
45x < -8
Step 3: Divide both sides by 45
45x/45 < -8/45
x < -8/45
Step 4: Graph
16% of 242 = ?
Please help me solve this
Answer:
16% of 242 = 38.72
Step-by-step explanation:
16% = 16/100 = 0.16
242 * 0.16 = 38.72
Answer:
38.72
Step-by-step explanation:
242 * .16 = 38.72
10) How many possible outfit combinations come from six shirts, three
slacks, and five ties? *
A 15
B 18
C 30
D 90
Answer:
The answer is D)90
Hope I helped
Suppose that the height (in centimeters) of a candle is a linear function of the amount of time (in hours) it has been burning. After 9 hours of burning, a candle has a height of 25.4 centimeters. After 23 hours of burning, its height is 19.8 centimeters. What is the height of the candle after 22 hours?
Answer:
Suppose that the height (in centimeters) of a candle is a linear function of
the amount of time (in hours) it has been burning.
After 11 hours of burning, a candle has a height of 23.4 centimeters.
After 30 hours of burning, its height is 12 centimeters.
What is the height of the candle after 13 hours?
:
Assign the given values as follows:
x1 = 11; y1 = 23.4
x2 = 30; y2 = 12
:
Find the slope using: m = %28y2-y1%29%2F%28x2-x1%29
m = %2812-23.4%29%2F%2830-11%29 = %28-11.4%29%2F19
:
Find the equation using the point/slope formula: y - y1 = m(x - x1)
y - 23.4 = -11.4%2F19(x - 11)
y - 23.4 = -11.4%2F19x + 125.4%2F19
y = -11.4%2F19x + 125.4%2F19 + 23.4
y = -11.4%2F19x + 125.4%2F19 + 23.4
y = -11.4%2F19x + 125.4%2F19 + 444.6%2F19
y = -11.4%2F19x + 570%2F19
y = -11.4%2F19x + 30, is the equation
:
What is the height of the candle after 13 hours?
x = 13
y = -11.4%2F19(13) + 30
y = -148.2%2F19 + 30
y = -7.8 + 30
y = 22.2 cm after 13 hrs
You sell tickets at school for fundraisers. You sold car wash tickets, silly string fight tickets and dance tickets – for a total of 380 tickets sold. The car wash tickets were $5 each, the silly sting fight tickets were $3 each and the dance tickets were $10 each. If you sold twice as many silly string tickets as car wash tickets, and you have $1460 total. Write the matrix in the box below. Write the solution set for this system and include any necessary work.
Answer:
Matrix :
[tex]\begin{bmatrix}1&1&1&|&380\\ 5&3&10&|&1460\\ -2&1&0&|&0\end{bmatrix}[/tex]
Solution Set : { x = 123, y = 246, z = 11 }
Step-by-step explanation:
Let's say that x represents the number of car wash tickets, y represents the number of silly sting fight tickets, and z represents the number of dance tickets. We know that the total tickets = 380, so therefore,
x + y + z = 380,
And the car wash tickets were $5 each, the silly sting fight tickets were $3 each and the dance tickets were $10 each, the total cost being $1460.
5x + 3y + 10z = 1460
The silly string tickets were sold for twice as much as the car wash tickets.
y = 2x
Therefore, if we allign the co - efficients of the following system of equations, we get it's respective matrix.
System of Equations :
[tex]\begin{bmatrix}x+y+z=380\\ 5x+3y+10z=1460\\ y=2x\end{bmatrix}[/tex]
Matrix :
[tex]\begin{bmatrix}1&1&1&|&380\\ 5&3&10&|&1460\\ -2&1&0&|&0\end{bmatrix}[/tex]
Let's reduce this matrix to row - echelon form, receiving the number of car wash tickets, silly sting fight tickets, and dance tickets,
[tex]\begin{bmatrix}5&3&10&1460\\ 1&1&1&380\\ -2&1&0&0\end{bmatrix}[/tex] - Swap Matrix Rows
[tex]\begin{bmatrix}5&3&10&1460\\ 0&\frac{2}{5}&-1&88\\ -2&1&0&0\end{bmatrix}[/tex] - Cancel leading Co - efficient in second row
[tex]\begin{bmatrix}5&3&10&1460\\ 0&\frac{2}{5}&-1&88\\ 0&\frac{11}{5}&4&584\end{bmatrix}[/tex] - Cancel leading Co - efficient in third row
[tex]\begin{bmatrix}5&3&10&1460\\ 0&\frac{11}{5}&4&584\\ 0&\frac{2}{5}&-1&88\end{bmatrix}[/tex] - Swap second and third rows
[tex]\begin{bmatrix}5&3&10&1460\\ 0&\frac{11}{5}&4&584\\ 0&0&-\frac{19}{11}&-\frac{200}{11}\end{bmatrix}[/tex] - Cancel leading co - efficient in row three
And we can continue, canceling the leading co - efficient in each row until this matrix remains,
[tex]\begin{bmatrix}1&0&0&|&\frac{2340}{19}\\ 0&1&0&|&\frac{4680}{19}\\ 0&0&1&|&\frac{200}{19}\end{bmatrix}[/tex]
x = 2340 / 19 = ( About ) 123 car wash tickets sold, y= 4680 / 19 =( About ) 246 silly string fight tickets sold, z = 200 / 19 = ( About ) 11 tickets sold
Traci Lynn currently walks to school from her apartment, which is 1.3 miles away from her first class. She typically walks at a speed of 3 miles per hour. She is considering buying a used bicycle from Deseret Industries to ride to campus. Traci Lynn assumes that if she were riding a bike, she could go about 5 miles per hour. How many minutes could Traci Lynn save getting to class each morning if she were to ride the bike?
5 minutes in bike and by walking 1 hours 3 minutes
Traci Lynn saves getting to class each morning if she were to ride 6.12 minute
What formula is used to find the time?The formula is used to find the value of time is;
Time = Distance/speed
Given that Traci Lynn currently walks to school from her apartment, which is 1.3 miles away from her first class.
If she goes to school from the apartment by walking, then it will take time is;
Time = 1.3/3
Time = 0.43 hours
If she goes to school from the apartment by bicycle, then it will take time is;
Time = 1.3/5
Times = 0.26 hours
Therefore,
The time in minutes could Traci Lynn save getting to class each morning if She ride the bike is;
0.43 - 0.26
= 0.17 hours
= 0.17 x 36 = 6.12 minute
Hence, Traci Lynn saves getting to class each morning if she were to ride 6.12 minute
To know more about the Time formula click the link given below.
brainly.com/question/10470257
#SPJ2
An airplane travels 1200 miles in 4 hours with the wind. The same trip takes 5 hours against the wind. What is the speed of the plane in still air and what is the wind speed?
Answer:
Speed of plane in still air is 270 mph
Wind speed is 30 mph
Step-by-step explanation:
Check the picture.
The speed of the plane in still air is 270 mph and the speed of the wind will be 30 mph.
What is the distance formula?The distance traveled by an object is the product of the speed of an object and the time taken.
Distance = speed x time
An airplane travels 1200 miles in 4 hours with the wind. The same trip takes 5 hours against the wind.
Let the speed of the plane be x
The speed of wind be y
Distance covered with the wind = (x + y)t
1200 = (x + y)4
(x + y) = 1200/4
(x + y)= 300 .....(a)
Distance covered against the wind = (x - y)t
1200 = (x - y)5
(x - y) = 1200/5
(x - y) = 240 .......(b)
By solving both the equation
(x + y)= 300
(x - y) = 240
Therefore the values will be x= 270mph and y = 30 mph
Learn more about the distance formula:
https://brainly.com/question/15172156
Examine the two triangles. Are the triangles congruent? Justify your conclusions. If they are congruent, complete the following statement: "Yes, triangle __ congruent to triangle __ giving a detailed explanation of your reasoning. If they are not congruent, explain why you think so. Be specific in your answer and make sure to show your work.
Answer: The triangles are not congruent
==========================================
Explanation:
For triangle DEF, the missing angle D is
D+E+F = 180
D+80+60 = 180
D+140 = 180
D = 180-140
D = 40
While the missing angle K in triangle JKL is
J+K+L = 180
80+K+50 = 180
K+130 = 180
K = 180-130
K = 50
---------------------
The three angles for triangle DEF are
D = 40E = 80F = 60The three angles for triangle JKL are
J = 80K = 50L = 50We don't have all the angles matching up. We need to have the same three numbers (the order doesn't matter) show up for both triangles in order for the triangles to be congruent. This is because congruent triangles have congruent corresponding angles.
The only pair that matches is E = 80 and J = 80, but everything else is different. So there is no way the triangles are congruent.
Notice how triangle JKL has two congruent base angles (K = 50 and L = 50), so this triangle is isosceles. Triangle DEF is not isosceles as we have three different angles, so this triangle is scalene.
Subtract these polynomials.
(3x2 – 2x + 5) – (x2 + 3) =
Answer:
D. 2x^2 - 2x + 2
Step-by-step explanation:
(3x2 – 2x + 5) – (x2 + 3) add or subtract like terms
3x^2 - x^2 - 2x - 3 + 5 = 2x^2 - 2x + 2
Answer:
2x^2 - 2x + 2
Step-by-step explanation:
Ape-x
Which of the following is the correct equation for the distance formula for the points (x1, y1) and (x2,y2)?
A. D=sqrt (x2-x1)^2+(y2-y1)^2
B. D=sqrt (x2-y2)^2+(y1-x1)^2
C. D=sqrt -(y2-y1)^2+(x2-x1)^2
D. D=sqrt (x1-x2)^2+(y2-y1)^2
Answer:
A. D=sqrt( (x2-x1)^2+(y2-y1)^2 )
Step-by-step explanation:
The distance between two points is the root of the sum of the squares of the differences in their corresponding coordinates. The equation of choice A is the usual formulation.
__
Comment on answer choices
Because the square of a number is the same as the square of its opposite, the formula in choice D is also correct.
Points A( − 1, 7), B(2, 19), and C(3, y) are on the same line. Find y.
Answer: y=23
Step-by-step explanation:
If Points and A,B and C lines on the same line then they will have the same slopes so since we have the coordinates of A and B we will use the to write an equation in slope intercept form.
To write it in slope intercept form we will need to find the slope and the y intercept.
To find the slope you will find the change in the y coordinates and divide it by the change in the x coordinates.
Using the coordinates (-1,7) and (2,19) the y coordinates are 7 and 19 and the x coordinates are -1 and 2.
Slope : [tex]\frac{7-19}{-1-2} \frac{-12}{-3} = 4[/tex] In this case the slope is 4 so we will use that to find the y intercept by using point A coordinate.
The slope intercept formula says that y=mx +b where me is the slope and b is the y intercept.
7=4(-1) + b
7 = -4 + b
+4 +4
b= 11 The y intercept is 11.
Now we can write the whole equation as y=4x + 11 .
To answer the question now, where we need to find y , we will plot the x coordinate which is 3 into the equation and solve for y.
y = 4(3) + 11
y = 12 + 11
y = 23
Solve this and get 12 points
Answer:
9
Step-by-step explanation:
First, find x. Since x is the average of the three number, add the three up and then divided by three. Thus:
[tex]x=\frac{13+-16+6}{3}=3/3=1[/tex]
y is the cube root of 8. Thus:
[tex]y=\sqrt[3]{8}=2[/tex]
So:
[tex]x^2+y^3\\=(1)^2+(2)^3\\=1+8=9[/tex]
Answer:
ljih
Step-by-step explanation:
70 points! Please answer fast!
Answer:
slope = 2
Step-by-step explanation:
will make it so simple and short
slope = rise / run
slope = 6 / 3
slope = 2
Answer:
B
Step-by-step explanation:
The formula for slope is (y2-y1)/(x2-x1)
In this case it is (1+5)/(3-0)
6/3
2
Write in words how we would say the following
3 square
Answer:
Three to the second power
Step-by-step explanation:
Hey there!
3 square
Can be written as the following,
Three to the second power
Hope this helps :)
If 2( a^2 +b^2 ) = ( a+b)^2 , then
a. a+b =0
b. a =b
c. 2a =b
d. ab =0
Answer:
the answer is a=b
Step-by-step explanation:
ax+r=7 , solve for x
Answer:
3
Step-by-step explanation:
a is 4 and 3 is x so 4+3=7
Answer: a=2 {x=3} r=1. 2(3)+ 1= 7
Step-by-step explanation:
Transform the polar equation to a Cartesian (rectangular) equation: r= 4sinθ
options include:
x^2+y^2 = 4y
x^2+y^2 = -4
x^2+y^2 = 4
x^2+y^2 = -4y
Answer:
x^2 +y^2 = 4y
Step-by-step explanation:
Using the usual translation relations, we have ...
r^2 = x^2+y^2
x = r·cos(θ)
y = r·sin(θ)
Substituting for sin(θ) the equation becomes ...
r = 4sin(θ)
r = 4(y/r)
r^2 = 4y
Then, substituting for r^2 we get ...
x^2 +y^2 = 4y . . . . . matches the first choice
Please help quick !
Answer:
vertical angles
Step-by-step explanation:
Angle 1 and 3 are vertical angles. The angles are made from the same lines and share a vertex. They are opposite it each other
Jaime went to the mall with $42. If he bought a T-shirt and had $18 left, how much did the T-shirt cost Jaime in dollars?
Answer:
$24
Step-by-step explanation:
You simply do $42-$18
=24
Answer:
$24
Step-by-step explanation:
At the start, Jaime had $42. In order to find out how much the T-shirt he purchased costs, we must subtract 18 from 42.
42 - 18 = 24
Jaime spent $24 on the T-shirt.
Which values of x are point(s) of discontinuity for this function? Function x = –4 x = –2 x = 0 x = 2 x = 4
Answer:
x=0 and x=2
Step-by-step explanation:
We need to check at each point where the function changes definition
At x= -2
On the left side -4 on the right side = -( -2)^2 = -4 continuous
At x=0
The point is not defined since neither side has an equals sign
discontinuous
x =2
on the left side 2^2 =4 on the right side 2
It is discontinuous
Answer:
x = 0
x = 2
Step-by-step explanation:
Edge 2020
~theLocoCoco
Question: Complete the point-slope equation of the line through (1,3)and (5,1). Use exact numbers. Equation: y-3=(Answer ?)
Answer:
y - 3 = -1/2(x - 1)
Step-by-step explanation:
Hey there!
Well point slope form is,
[tex]y - y_{1} = m(x - x_{1})[/tex]
We can use the point (1,3)
y - 3 = m(x - 1)
Now we need to find slope with the following formula,
[tex]\frac{y^2-y^1}{x^2-x^1}[/tex], we’ll use the points (1,3) and (5,1).
[tex]\frac{1-3}{5-1}[/tex]
-2/4
Slope or m = -1/2
y - 3 = -1/2(x - 1)
Hope this helps :)
Find the common ratio for the following sequence. Type a numerical answer in the space provided. If necessary, use the
/ key to represent a fraction bar. Do not type spaces in your answer.
2,-2, 2, -2, ...
Answer:
-1
Step-by-step explanation:
the common ratio in this geometric series is -1
What did this person do wrong? Honestly really stuck and do not remember geometry!
Answer:
See below.
Step-by-step explanation:
Using the right triangle altitude theorem, the correct proportions are:
[tex] \dfrac{AB}{AC} = \dfrac{AC}{AD} [/tex]
[tex] \dfrac{AB}{x} = \dfrac{x}{AD} [/tex]
[tex] \dfrac{25}{x} = \dfrac{x}{16} [/tex]
[tex] x^2 = 25 \times 16 [/tex]
[tex] x = 20 [/tex]
AC = 20 cm
[tex] \dfrac{AB}{CB} = \dfrac{CB}{DB} [/tex]
[tex] \dfrac{AB}{y} = \dfrac{y}{DB} [/tex]
[tex] \dfrac{25}{y} = \dfrac{y}{9} [/tex]
[tex]y^2 = 25 \times 9[/tex]
[tex]y = 15[/tex]
CB = 15 cm
A TV Dinner Company Sells Three Types Of Dinners: A Chicken Dinner For $10, A Beef Dinner For $11, Or A Fish Dinner For $12. At One Particular Grocery Store, They Sold 200 Dinners For A Grand Total Of $2138. Required:a. If they sold three times as many chicken dinners as they did fish, then how many of each kind of dinner did they sell?b. Find the equation of the quadratic function that passes through the points (−1, 9), (2, 6), and (3, 17). Write your answer in the form y = ax2+bx+c.
Answer:
a) The company sold 93 Chicken dinners, 76 Beef dinners and 31 Fish dinners.
b) [tex]y=3x^{2}-4x+2[/tex]
Step-by-step explanation:
a)
In order to solve part a of the problem, we must start by setting our variables up:
C=# of Chicken dinners
B=# of Beef dinners
F=# of Fish dinners
Next we can use these variables to build our equations. We start by taking the fact that they sold a total of 200 dinners. The sum of all the variables should add up to that so we get:
C+B+F=200
Then the problem tells us the price of each dinner and the total amount of money they made from selling the dinners that day:
"A TV Dinner Company Sells Three Types Of Dinners: A Chicken Dinner For $10, A Beef Dinner For $11, Or A Fish Dinner For $12. For A Grand Total Of $2138"
So we can use this information to build our second equation:
10C+11B+12F=2138
We have two equations now but three variables, so we need an additional equation so we can finish solving this. The problem tells us that:
"they sold three times as many chicken dinners as they did fish"
which translates to:
C=3F
so now we have enough information to finish solving the problem. We can start by substituting the last equation into the previous two equations so we get:
C+B+F=200
3F+B+F=200
4F+B=200
and
10C+11B+12F=2138
10(3F)+11B+12F=2138
30F+11B+12F=2138
42F+11B=2138
So now we can take the two bolded equations and solve them simultaneously. We can solve them by using any method we wish. Let's solve it by substitution.
We start by solving the first equation for B so we get:
B=200-4F
and now we substitute it into the second equation:
42F+11(200-4F)=2138
and now we solve for F
42F+11(200-4F)=2138
42F+2200-44F=2138
-2F=2138-2200
[tex]F=\frac{-62}{-2}[/tex]
F=31
So now that we know the value of F, we can find the values of the rest of the variables so we can take the previous equations to figure this out:
B=200-4F
B=200-4(31)
B=200-124
B=76
and finally:
C=3F
C=3(31)
C=93
So
The company sold 93 Chicken dinners, 76 Beef dinners and 31 Fish dinners.
b) For the second part of the problem we need to build a system of equations to find the equation we are looking for. We were given three points:
(-1,9), (2,6) and (3,17)
so we need to substitute each of the points on the given quadratic equation so we get:
[tex]9=a(-1)^{2}+b(-1)+c[/tex]
eq.1: [tex]9=a-b+c[/tex]
[tex]6=a(2)^{2}+b(2)+c[/tex]
eq. 2: [tex]6=4a+2b+c[/tex]
[tex]17=a(3)^{2}+b(3)+c[/tex]
eq. 3: [tex]17=9a+3b+c[/tex]
So now that we have our three equations we can solve them simultaneously to get the values of a, b and c by using the method you feel more comfortable with. Let's solve it by elimination:
So let's take the first equations and let's subtract them:
[tex]9=a-b+c[/tex]
[tex]-6=-4a-2b-c[/tex]
-------------------------------
3=-3a-3b
And now we repeat the process with the first and third equations:
[tex]9=a-b+c[/tex]
[tex]-17=-9a-3b-c[/tex]
-------------------------------
-8=-8a-4b
So now we have two new equations we can solve simultaneously, but they can be simplified by dividing the first one into -3 and the second one into -4 so they become:
a+b=-1
2a+b=2
We can now solve them by substitution. Let's solve the first one for a and then let's substitute it into the second equation:
a=-1-b
let's substitute
2(-1-b)+b=2
and solve for b
-2-2b+b=2
-b=4
b=-4
Now we can find a:
a=-1-b
a=-1+4
a=3
and now we can find c:
c=9-a+b
c=9-3-4
c=2
So we can use these answers to build our equation:
[tex]y=ax^{2}+bx+c[/tex]
[tex]y=3x^{2}-4x+2[/tex]
4(c+3) =4+c+c+c+c+17
The simplified form of the expression (5.23x + 3.76) − (3.67x − 6.39) is?
Answer:
1.56x+10.15
Step-by-step explanation:
Answer:
1.56x + 10.15
Step-by-step explanation:
(5.23x + 3.76) – (3.67x – 6.39)
(a + b) – (c – d) = a + b – c + d
Remove the parentheses and change the signs as needed:
5.23x + 3.76 – 3.67x + 6.39.
Group the like terms and simplify:
5.23x – 3.67x + 3.76 + 6.39
1.56x +10.15.
The simplified form of (5.23x + 3.76) – (3.67x – 6.39) is 1.56x + 10.15.
If the nth term is nn+1, then the (n+1)st term is:
Answer:
[tex]\large \boxed{\sf C. \ (n+1)^{n+1}+1}[/tex]
Step-by-step explanation:
[tex]n^n+1[/tex]
Plug in the value for n as n+1 in the nth term to find the (n+1)st term.
[tex](n+1)^{n+1}+1[/tex]
Answer:
[tex]\boxed{Option \ 3}[/tex]
Step-by-step explanation:
=> [tex]n^n+1[/tex]
Given that n = n+1
So,
=> [tex](n+1)^{n+1}+1[/tex]
1. Quadratics: The path of the longest shot put by the Women’s track team at Sun Devil U is modeledby h(x) = -0.015x2 + 1.08x + 5.8, where x represents the horizontal distance from the start and h(x) isthe height of the shot put above the ground. (Both x and h(x) are measured in feet.)a. [3 pts] Determine h(24). Round your answer to 2 decimal places.
Answer:
23.08 feetStep-by-step explanation:
If the path of the longest shot put by the Women’s track team at Sun Devil U is modeled by h(x) = -0.015x² + 1.08x + 5.8 where x represents the horizontal distance from the start and h(x) is the height of the shot put above the ground, to determine h(24), we will have to substitute x = 24 into the modeled equation as shown;
[tex]h(x) = -0.015x^2 + 1.08x + 5.8\\\\if \ x = 24;\\\\h(24) = -0.015(24)^2 + 1.08(24) + 5.8\\\\h(24) = -0.015(576)+25.92+5.8\\\\h(24) = -8.64+31.72\\\\h(24) = 23.08\\[/tex]
Hence the value of the height at the horizontal distance of 24 feet is 23.08 feet to 2 decimal place.
An engineer wishes to determine the width of a particular electronic component. If she knows that the standard deviation is 3.6 mm, how many of these components should she consider to be 90% sure of knowing the mean will be within ± 0.1 ±0.1 mm?
Answer:
She must consider 3507 components to be 90% sure of knowing the mean will be within ± 0.1 mm.
Step-by-step explanation:
We are given that an engineer wishes to determine the width of a particular electronic component. If she knows that the standard deviation is 3.6 mm.
And she considers to be 90% sure of knowing the mean will be within ±0.1 mm.
As we know that the margin of error is given by the following formula;
The margin of error = [tex]Z_(_\frac{\alpha}{2}_) \times \frac{\sigma}{\sqrt{n} }[/tex]
Here, [tex]\sigma[/tex] = standard deviation = 3.6 mm
n = sample size of components
[tex]\alpha[/tex] = level of significance = 1 - 0.90 = 0.10 or 10%
[tex]\frac{\alpha}{2} = \frac{0.10}{2}[/tex] = 0.05 or 5%
Now, the critical value of z at a 5% level of significance in the z table is given to us as 1.645.
So, the margin of error = [tex]Z_(_\frac{\alpha}{2}_) \times \frac{\sigma}{\sqrt{n} }[/tex]
0.1 mm = [tex]1.645 \times \frac{3.6}{\sqrt{n} }[/tex]
[tex]\sqrt{n} = \frac{3.6\times 1.645}{0.1 }[/tex]
[tex]\sqrt{n}[/tex] = 59.22
n = [tex]59.22^{2}[/tex] = 3507.0084 ≈ 3507.
Hence, she must consider 3507 components to be 90% sure of knowing the mean will be within ± 0.1 mm.
