Answer:
-28
Step-by-step explanation:
if c = 3 and x = -5 than,
-c + 5x = -3 + 5 * (-5) = -3 + (-25) = - 28
The 11th term of an arithmetic progression is 14 and the sum of the first 26 terms is 416. Find the first term and the common difference.
Answer:
The first term is 6; the common difference in 0.8.
Step-by-step explanation:
The nth term is:
[tex] a_n = a_1 + (n - 1)d [/tex]
The sum of the first n terms is:
[tex] S_n = \dfrac{n(a_1 + a_n)}{2} [/tex]
[tex] a_{n} = a_1 + (n - 1)d [/tex]
[tex] a_{11} = a_1 + (11-1)d [/tex]
[tex] a_1 + 10d = 14 [/tex] Equation 1
[tex] S_n = \dfrac{n(a_1 + a_n)}{2} [/tex]
[tex] S_{26} = \dfrac{26(a_1 + a_{26})}{2} [/tex]
[tex] \dfrac{26(a_1 + a_1 + 25d}{2} = 416 [/tex]
[tex] \dfrac{52a_1 + 650d)}{2} = 416 [/tex]
[tex] 26a_1 + 325d = 416 [/tex] Equation 2
Equation 1 and Equation 2 form a system of equations in 2 unknowns.
To eliminate a_1, subtract 26 times Eq. 1 from Eq. 2.
[tex] 65d = 52 [/tex]
[tex] d = \dfrac{52}{65} [/tex]
[tex] d = \dfrac{4}{5} = 0.8 [/tex]
[tex] a_1 + 10d = 14 [/tex]
[tex] a_1 + 10 \times 0.8 = 14 [/tex]
[tex] a_1 + 8 = 14 [/tex]
[tex] a_1 = 6 [/tex]
Answer:
The first term is 6; the common difference in 0.8.
Which descriptions from the list below accurately describe the relationship
between AABC and ADEF? Check all that apply.
E
37
B
10
8
5 37
4
534 D
A 3 C
53°
D
6
F
A. Same area
O B. Same size
C. Congruent
D. None of the above
Hi
Answer:
D. None of the above
Step-by-step explanation:
Both triangles have the same shape but different size. Their area cannot be the same. Also, the ratio of their corresponding side lengths are the same.
Thus:
8/4 = 10/5 = 6/3 = 2
This implies that both triangles are similar.
Therefore, both triangles cannot have the same area, they are not of the same size and cannot be congruent to each other.
People think that that babies are equally likely to be either boys or girls. Actually, about 51.3% of all babies are boys. If a family has two children (not twins), what is the chance both children are boys
Answer:
26.32%
Step-by-step explanation:
The probability that both children are boys would be a sequence of events. Therefore, in order to calculate this we need to multiply the probability of the first baby being a boy with the probability of the second baby being a boy. Since the probability of any baby being a boy is 51.3%, we simply multiply this value in decimal form by itself.
51.3 / 100 = 0.513
0.513 * 0.513 = 0.263169 or 26.32%
Public health officials claim that people living in low income neighborhoods have different Physical Activity Levels (PAL) than the general population. This is based on knowledge that in the U.S., the mean PAL is 1.65 and the standard deviation is 0.55. A study took a random sample of 51 people who lived in low income neighborhoods and found their mean PAL to be 1.63. Using a one-sample z test, what is the z-score for this data
Answer:
The z-score for this data is Z = -0.26.
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]
This is based on knowledge that in the U.S., the mean PAL is 1.65 and the standard deviation is 0.55.
This means that [tex]\mu = 1.65, \sigma = 0.55[/tex]
A study took a random sample of 51 people who lived in low income neighborhoods and found their mean PAL to be 1.63.
This means that [tex]n = 51, X = 1.63[/tex]
Using a one-sample z test, what is the z-score for this data
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{1.63 - 1.65}{\frac{0.55}{\sqrt{51}}}[/tex]
[tex]Z = -0.26[/tex]
The z-score for this data is Z = -0.26.
Simply the following expression 3^0
Answer:
1
Step-by-step explanation:
3^0
Anything raised to the zero power is 1
3^0 =1
Answer:
1
Step-by-step explanation:
Anything to the power of 0 is 1
Eg: 5⁰ = 1
a⁰= 1
(-12)⁰ = 1
The scores on a psychology exam were normally distributed with a mean of 69 and a standard deviation of 4. What is the standard score for an exam score of 68?
The standard score is ?
Answer:
0.25
Step-by-step explanation:
Given that :
Mean score, μ = 69
Standard deviation, σ = 4
Score, x = 64
The standardized score, Zscore can be obtained using the formular :
Zscore = (x - μ) / σ
Zscore = (69 - 68) / 4
Zscore = 1 / 4
Zscore = 0.25
The five-number summary of a data set is: 0, 4, 6, 14, 17
An observation is considered an outlier if it is below:
An observation is considered an outlier if it is above:
Answer:
Outlier therefore could only be values below - 12.75
or could only be values above + 121.125
Step-by-step explanation:
0, 4, 6, 14, 17
inner quartile range of 0 - 17 is 1/2 of 17 subtracted from the higher number = 17 - 1/2 of 8.5 = 8.5 - 4.25 = 4.25 - 4.25 x 3
= 4.25 to 12.75 for inner quartile
inner quartile range is 12.75-4.25 = 8.5
We then 1.5 x 8.5 to show the outlier
= 12.75 meaning there is no outlier if is below.
Lower quartile fences = 4.25 - 1.5 = 2.75
or -1.5 x 8.5 (the range) = -12.75
Upper quartile fence = 12.75 + 1.5 = 14.25 x 8.5 = 121.125 this would be an outlier if it is 12.75 higher than 121.125 or 12.75 lower than 5.50.
Outlier therefore could only be values below - 12.75
or could only be values above + 121.125
An observation is considered an outlier if it exceeds a distance of 1.5 times the interquartile range (IQR) below the lower quartile or above the upper quartile. The values of the lower quartile - 1.5 x IQR and upper quartile + 1.5 x IQR are known as the inner fences.
An observation is an outlier if it falls more than above the upper quartile or more than below the lower quartile. The minimum value is so there are no outliers in the low end of the distribution. The maximum value is so there are no outliers in the high end of the distribution.
The average of 6,10,x,20 and 30 is 18. what is the value of x
Answer:
24
Step-by-step explanation:
18 times 5 is 90 so that means that the given numbers have to add up to 90 (including x)
so,
6+10+20+30=66
90-66=24
I hope this helps!
Answer:
[tex]x = 24[/tex]
Step-by-step explanation:
[tex]6 + 10 + x + 20 + 30 = 18[/tex]
There are 5 numbers that we must add to average out to get 18 so let set this equation up
[tex] \frac{6 + 10 + x + 20 + 30}{5} = 18[/tex]
[tex]6 + 10 + x + 20 + 30 = 90[/tex]
[tex]x = 24[/tex]
Solve the following equation or inequality for the unknown variable. Round answer to two decimal places if necessary.
(3x)2 - 10 = 56
4
x =
Answer:
x = 2.7
Step-by-step explanation:
The given equation is :
[tex](3x)^2-10=56[/tex]
We need to solve it for x.
It can be rewrite as follows:
[tex]9x^2-10=56[/tex]
Adding 10 to both sides,
[tex]9x^2-10+10=56+10\\\\9x^2=66\\\\x=\sqrt{\dfrac{66}{9}}\\\\x=2.70[/tex]
So, the value of x is equal to 2.7.
When the Bucks play Chiefs at football, the probability that the Chiefs, on present form, will win is 0.56. In a competition, these teams are to play two more pgames. If Swallows beats Bucks in at least4one of these games, they will win the competition, otherwise Bucks will win the trophy. NB: Round off to 2 decimal places. a. The probability that Swallows will win the trophy is [a] probability that Rucks will win the trophy is
Answer:
The probability that Swallows will win the trophy is 0.8064
The probability that Rucks will win the trophy is 0.1936
Step-by-step explanation:
For each game, there are only two possible outcomes. Either the Swallows win, or they do not. The probability of them winning a game is independent of any other game, which means that the binomial probability distribution is used.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
And p is the probability of X happening.
Probability the Swallows wins is 0.56
This means that [tex]p = 0.56[/tex]
2 games:
This means that [tex]n = 2[/tex]
The probability that Swallows will win the trophy is
Probability they win at least one game, so:
[tex]P(X \geq 1) = 1 - P(X = 0)[/tex]
In which
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{2,0}.(0.56)^{0}.(0.44)^{2} = 0.1936[/tex]
Then
[tex]P(X \geq 1) = 1 - 0.1936 = 0.8064[/tex]
0.8064 = 80.64% probability the Swallows win the trophy and 0.1936 probability that the Rucks win the trophy.
No more than one state of nature can occur at a given time for a chance event. This indicates that the states of nature are defined such that they are
a. conservative events.
b. mutually exclusive.
c. independent outcomes.
d. collectively exhaustive.
Answer:
b. mutually exclusive.
Step-by-step explanation:
The given description is an illustration of mutually exclusive events.
Take for instance, when you roll a die;
It is impossible to have an outcome of 2 and 6 at the same time; these means that 2 and 6 are mutually exclusive.
In a nutshell, when two or more sates of events/states of nature can not happen at the same time; such events/states of nature are mutually exclusive.
Latoya paid $12.24 for a 6.35 kg bag of food. a few weeks later, she paid $13.99 for a 7.48 kg bag at a different store. Find the unit price for each bag.
Answer:
1.92755 ,1.870320 i hope it will help you
Answer:
First bag's unit price=$1.92 per kg Second bag's unit price=$1.87 per kg
Step-by-step explanation:
1.92 becomes 1.93
Please help me i will give brainlest please i need help
Answer:
Since you didn't mention which question.
Step-by-step explanation:
13.
[tex]1.\overline{52}\\[/tex] = 1.525252...
Let x = 1.525252...
10x = 15.2525252....
100x = 152.525252...
100x - x = 151.00
99x = 151
[tex]x = \frac{151}{99}\\\\or\\\\x = 1 \frac{52}{99}[/tex]
14.
4x + 10 = 8x - 26 [ corresponding angles are congruent ]
4x - 8x = - 26 - 10
- 4x = - 36
[tex]x = \frac{-36}{-4} \\\\x = 9[/tex]
15.
Given breadth of a rectangle is ( 2/3) its length.
Let the length be x
Therefore, breadth = ( 2 /3) of x
[tex]= \frac{2}{3} \times x\\\\=\frac{2}{3}x[/tex]
Given perimeter = 40m
Perimeter of a rectangle = 2( length + breadth)
[tex]40 = 2 (x + \frac{2}{3}x )\\\\\frac{40}{2} = \frac{2}{2}(x + \frac{2}{3}x)\\\\20 = x + \frac{2}{3}x\\\\20 = \frac{3x + 2x}{3}\\\\20 \times 3 = 5x \\\\x = \frac{60}{5}\\\\x = 12\\\\Therefore, Length = x = 12 \ m \ and \ breadth = \frac{2}{3}x = \frac{2}{3} \times 12 = 8 \ m[/tex]
16.
Sum of the angles of a triangle = 180°
Given ratio = 2 : 3 : 4
Sum of the ratio = 9
Therefore,
[tex]first \ angle = \frac{2}{9} \times 180 = 2 \times 20 = 40 ^\circ\\\\Second \ angle = \frac{3}{9} \times 180 = 3 \times 20 = 60^\circ\\\\Third angle = \frac{4}{9} \times 180 = 4 \times 20 = 80^\circ[/tex]
17.
Sum of interior angles of a polygon with n sides = ( n - 2) x 180°
Given polygon is pentagon, that is n = 5
Therefore, sum of the interior angles = ( 5 - 2) x 180 = 3 x 180 = 540°
That is ,
x + 125 + 125 + 88 + 60 = 540°
x + 398 = 540°
x = 540 - 398
x = 142°
Answer:
Please can you say which question?
Thank you
The slope of a line is 2 and the point (1, 1) lies on the line. What is the y-intercept of this line? (0, -1) (0, 5) (-2, 0)
Answer:
(0, -1)
Step-by-step explanation:
It's helpful if we think of slope in the context of rise over run.
Since the point (1, 1) lies on the line, because of the slope 2, if we subtract x by 1 to get to x = 0, then we'll be subtracting y by 2.
By that logic, the answer must be (0, -1).
Calculate the perimeter
Answer:
sorry i cannot help you
Next anyone help it always helps haha 20 points
Answer:
Distance between Amber and Claire's house = 17.63 blocks
Step-by-step explanation:
In this graph three points are showing the locations of Amber's, Betsey's and Claire's houses.
Each unit on the graph represents 1 block.
Amber walks from her house to Claire's house, then on to Betsey's house.
We have to calculate the distance covered by Amber.
Since Distance from Claire's house to Betsey's house = 7 blocks = 7 units
and distance between Amber and Betsey's house = 8 blocks = 8 units
Now we will calculate the distance between Amber and Claire's house by Pythagoras theorem.
Distance² = 7² + 8² = 49 + 64 = 113
Distance = √113 units = 10.63 units
Therefore, total distance walked by Amber = 10.63 + 7 = 17.63 units = 17.63 blocks
Answer:
the answer might be 17. 63 because there are 7 blocks in between them so try that sorry if its wrong
When 100 engines are shipped, all of them are free of defects. Select a written description the complement of the given event
A) At most one of the engines is defective.
B) All of the engines are defective.
C) At least one of the engines is defe
D) None of the engines are defective
Answer:
Option C
Step-by-step explanation:
Suppose that we have a given proposition p
We define the complement as:
"NOT p" or ¬p
So, if p is:
the dog is red
the complement is
the dog is NOT red.
The principal rule to work with this is:
if p is true, then ¬p is false
if p is false, then ¬p is true.
Here the proposition is:
p = "When 100 engines are shipped, all of them are free of defects."
When this is this is true, ¬p must be false.
when this is false, ¬p must be true.
Let's analyze the given options, first the incorrect ones:
A: "At most one of the engines is defective."
here if we have for example, two defective engines, then this proposition and the original proposition are false.
B: " All of the engines are defective."
Here if there is one defective engine, then this is false, and also is the original proposition.
D: "None of the engines are defective"
When the original proposition is true "When 100 engines are shipped, all of them are free of defects.", this proposition is also true (because none of the engines are defective)
Finally, the corrrect one
C "At least one of the engines is defective"
When the original proposition is true, there are no defective engines, so this is false.
While, if this is true, there is at least one defective engine, so the original proposition is false.
Then this is the correct option:
¬p = "At least one of the engines is defective"
Question 8 of 9
Use a calculator to find the correlation coefficient of the data set.
у
2
15
6
13
7
8
12
X
15
13
9
8
5
A. -0.909
B. 0.909
C. 0.953
D. -0.953
Actual data table :
X __ y
2 15
6 13
7 9
8 8
12 5
Answer:
0.953
Step-by-step explanation:
The question isnt well formatted :
The actual data:
X __ y
2 15
6 13
7 9
8 8
12 5
Using a correlation Coefficient calculator, the correlation Coefficient obtained by fitting the data is 0.953 which depicts a strong linear correlation between the x and y variable. This shows that the value of y increases with a corresponding increase in x values and vice versa.
Complete the following statement.
Answer:
Hello dude
[tex] - 1 \frac{21}{24} + 1 \frac{22}{24} = + \frac{1}{24} [/tex]
so it's positive
HAVE A NİCE DAY
Step-by-step explanation:
GREETİNGS FROM TURKEY ツ
1. What is the area of the figure below? (1 point)
5 in.
3 in.
12 in
O 18 in.2
O 30 in.2
O 36 in.2
O 60 in.2
Answer: 36in2
Step-by-step explanation:
A= base *height
=12*3
=36
The Area of the figure is 36 in².
What is Area of parallelogram?The area of a parallelogram refers to the total number of unit squares that can fit into it and it is measured in square units (like cm2, m2, in2, etc). It is the region enclosed or encompassed by a parallelogram in two-dimensional space.
two equal, opposite sides,two intersecting and non-equal diagonals, andopposite angles that are equalThe area of a parallelogram can be calculated by multiplying its base with the altitude. The base and altitude of a parallelogram are perpendicular to each other. The formula to calculate the area of a parallelogram can thus be given as,
Area of parallelogram = b × h square units
where,
b is the length of the base
h is the height or altitude
Given:
base= 12 in
height= 3 in
Area of parallelogram,
= base * height
=12* 3
= 36 in²
Learn more about Area of parallelogram here:
https://brainly.com/question/16052466
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a. The first five terms of n^2 + 5 are
Given:
The nth term of a sequence is:
[tex]n^2+5[/tex]
To find:
The first five terms of the given sequence.
Solution:
The given sequence is:
[tex]a_n=n^2+5[/tex]
For n=1,
[tex]a_1=1^2+5[/tex]
[tex]a_1=1+5[/tex]
[tex]a_1=6[/tex]
For n=2,
[tex]a_2=2^2+5[/tex]
[tex]a_2=4+5[/tex]
[tex]a_2=9[/tex]
For n=3,
[tex]a_3=3^2+5[/tex]
[tex]a_3=9+5[/tex]
[tex]a_3=14[/tex]
For n=4,
[tex]a_4=4^2+5[/tex]
[tex]a_4=16+5[/tex]
[tex]a_4=21[/tex]
For n=5,
[tex]a_5=5^2+5[/tex]
[tex]a_5=25+5[/tex]
[tex]a_5=30[/tex]
Therefore, the first five terms of the given sequence are 6, 9, 14, 21, 30.
Please answer this question -+ is equals to what
Answer:
It means that there are two answers, a positive one and a negative one.
Step-by-step explanation:
If you get +-5, then you have two answers: +5 and -5
Which of the following statements about points are false?
Check all that apply.
A. Their sizes vary.
B. They have no size and no dimensions,
C. They have no length or height.
D. Their size depends on their dimensions.
Answer:
their sizes vary
Step-by-step explanation:
their sizes vary
Approximate 5.7255 to the nearest thousand
round 5.7255 to thousands place
place after thousands place (5) rounds up the 5 before it
therefore 5.726 ur ans
MARK above ANS as branliest
Find the equation of the line tangent to y = sin(x) going through х = pi/4
Answer:
[tex]\displaystyle y - \frac{\sqrt{2}}{2} = \frac{\sqrt{2}}{2} \bigg( x - \frac{\pi}{4} \bigg)[/tex]
General Formulas and Concepts:
Algebra I
Coordinates (x, y)
Functions
Function Notation
Point-Slope Form: y - y₁ = m(x - x₁)
x₁ - x coordinate y₁ - y coordinate m - slopePre-Calculus
Unit CircleCalculus
Derivatives
The definition of a derivative is the slope of the tangent lineDerivative Notation
Trig Derivative: [tex]\displaystyle \frac{d}{dx}[sin(u)] = u'cos(u)[/tex]
Step-by-step explanation:
Step 1: Define
Identify
[tex]\displaystyle y = sin(x)[/tex]
[tex]\displaystyle x = \frac{\pi}{4}[/tex]
Step 2: Differentiate
Trig Derivative: [tex]\displaystyle y' = cos(x)[/tex]Step 3: Find Tangent Slope
Substitute in x [Derivative]: [tex]\displaystyle y' \bigg( \frac{\pi}{4} \bigg) = cos \bigg( \frac{\pi}{4} \bigg)[/tex]Evaluate [Unit Circle]: [tex]\displaystyle y' \bigg( \frac{\pi}{4} \bigg) = \frac{\sqrt{2}}{2}[/tex]Step 4: Find Tangent Equation
Substitute in x [Function y]: [tex]\displaystyle y \bigg( \frac{\pi}{4} \bigg) = sin \bigg( \frac{\pi}{4} \bigg)[/tex]Evaluate [Unit Circle]: [tex]\displaystyle y \bigg( \frac{\pi}{4} \bigg) = \frac{\sqrt{2}}{2}[/tex]Substitute in variables [Point-Slope Form]: [tex]\displaystyle y - \frac{\sqrt{2}}{2} = \frac{\sqrt{2}}{2} \bigg( x - \frac{\pi}{4} \bigg)[/tex]Topic: AP Calculus AB/BC (Calculus I/I + II)
Unit: Derivatives
Book: College Calculus 10e
Will give brainliest answer
Answer:
not equivalent
equivalent
not equivalent
Step-by-step explanation:
25 is by itself already 5²
therefore
[tex] {25}^{m} = {5}^{2m} [/tex]
when we divide one time by 5, we simply take away 1 from the power making it
[tex] {5}^{2m - 1} [/tex]
the other options are wrong
[tex] {25}^{m - 1} [/tex]
would be right, if we have
[tex] {25}^{m} \div 25[/tex]
but we don't.
and
[tex] {25}^{2m - 1} [/tex]
would even square
[tex] {25}^{m} [/tex]
and then divide by 25. no, the original excision is nothing like that.
Help please!!!!!!!!!!!!!!!!!!
If 6 playes cost 54$ how much do 30 plates cost
Answer:
270 plates
Step-by-step explanation:
First, you need to find how much one plate costs.
6x = 54
---- ----
6 6
x = 9
Now, multiply 30 plates with x, which is 9.
30(9) = 270
The answer is 270.
Answer:
270
Step-by-step explanation:
54($)÷6= 9 then 9×30=270
whitch numbre produces a rational number when multiplied by 1/3 ?
Answer:
Step-by-step explanation:
multiplication of two rational numbers produce a rational number.
The Goodman Tire and Rubber Company periodically tests its tires for tread wear under simulated road conditions. To study and control the manufacturing process, 20 samples, each containing three radial tires, were chosen from different shifts over several days of operation; the data collected are shown below. Assuming that these data were collected when the manufacturing process was believed to be operating in control, develop the R and charts.
R Chart: (to 2 decimals)
UCL =
LCL =
Chart: (to 1 decimal)
UCL =
LCL =
Answer:
Range:
UCL = 4.73
LCL = 18.08
MEAN :
UCL = 27.115
LCL = 31.219
Step-by-step explanation:
Given the data:
The mean and range of each sample :
Sample __ Thread wear __ xbar __ R
1 ___31 __ 42 ___ 28 ____ 33.67 _14
2___ 26 _ 18 ____35____ 26.33 _17
3___25 __30 ___ 34____29.67 _ 9
4 __ 17 __ 25 ___ 21 _____ 21 ___ 8
5 __ 38 _ 29 ___ 35 _____ 34 __ 9
6 __ 41 __42 ___36 _____39.67_ 6
7 __ 21 __ 17 ___29 _____22.33 _12
8 __ 32 __26___28 ____ 28.67 _ 6
9 __ 41 __ 34 __ 33 ______ 36 __8
10__29___17___30 _____25.33_ 13
11 __26 __ 31 __ 40 _____32.33_ 14
12__23 __ 19 __ 45 _____12.33 __6
13 __17 __ 24 __ 32_____24.33__15
14 __43__ 35___17_____ 31.67 _ 26
15__18 ___25__ 29_____ 24 ___ 11
16__30___42___31 ____34.33__ 12
17__28___36 __ 32____ 32 ____8
18__40 __ 29 __ 31 ____33.33 __ 11
19__18 ___29__ 28____ 25 ____11
20_ 22 __ 34 __ 26 ___ 27.33 __12
Size per sample, sample size, n = 3
Number of samples, k = 20
We calculate the sample mean and range average :
Sample mean, x-- = Σxbar/n = 29.167
Range average, Rbar = ΣR/n = 11.4
The mean control limit :
x-- ± A2Rbar
From the x chart ;
A2 for n = 20 is A2 = 0.180
29.167 ± 0.180(11.40)
LCL = 29.167 - 0.180(11.40) = 27.115
UCL = 29.167 + 0.180(11.40) = 31.219
The Range control limit :
Rbar(1 ± 3(d3/d2))
From the R-chart :
d2 at n = 20 ; d2 = 3.735
d3 at n = 20 ; d3 = 0.729
LCL = 11.40(1 - 3(0.729/3.735)) = 4.725
UCL = 11.40(1 + 3(0.729/3.735)) = 18.075