Standard deviation is a useful concept in performance management. Let us say that a director in a local fire department wants to know any variation between the performance of this year and that of the last year. He draws a sample of 10 response times of this year ( in minutes):

3.0, 12.0, 7.0, 4.0, 4.0, 6.0, 3.0, 9.0, 11.0, and 15.0, comparing them with a sample of 10 response times last year ( in minutes): 8.0, 7.0, 8.0, 6.0, 6.0, 9.0, 7.0, 9.0, 8.0, and 6.0.

Required:
a. Does he see a performance variation by the mean?
b. Does he see a performance variation by the standard deviation? If he does, is it performance improvement or deterioration from the last year? Why?

Answers

Answer 1

Answer:

Step-by-step explanation:

Given the data :

Response time this year :

3.0, 12.0, 7.0, 4.0, 4.0, 6.0, 3.0, 9.0, 11.0, 15.0

Response time last year :

8.0, 7.0, 8.0, 6.0, 6.0, 9.0, 7.0, 9.0, 8.0, 6.0

Let's calculate the mean and standard deviation of each data sample :

Mean(m) = Σ(X) / n

n = sample size = 4

This year:

ΣX = 74 ; n = 10

Mean = 74 /10 = 7. 4

Standard deviation(s) = √(Σ(x - m)²/n - 1)

s = 4.195

Using a calculator to save computation time :Standard deviation = 4.195

LAST YEAR :

ΣX = 74 ; n = 10

Mean = 74 /10 = 7. 4

Standard deviation(s) = √(Σ(x - m)²/n - 1)

Using a calculator to save computation time :Standard deviation = 1.17

a. Does he see a performance variation by the mean?

From the mean value obtained for the two years, both are the same, hence, the value does not signify a variation in performance.

b. Does he see a performance variation by the standard deviation? If he does, is it performance improvement or deterioration from the last year? Why?

Yes, the value of standard deviation are different with the current year having a value of 4.195 and the previous year, a value of 1.17

The variation shows there is a deterioration on this year's performance from last year due to the larger value of standard deviation obtained ; 4.195 > 1.17


Related Questions

Need helppppppppppppp

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I can’t see can you put it closer

What is
7c — 3 < — 7с — 28

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Answer:

Step-by-step explanation:

- c > -25.

Flip the sign because dividing by a negative

For question 5 plz :)

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Answer: b

Step-by-step explanation: i took the quiz

Answer B
I took this test like 100 years ago

A line passes through (10,5) and (13,-4). Write the equation of the line in standard form.
A.
3x - y = 5
B.
3x - y = 25
C.
3x + y = 25
D.
3x + y = 35

Answers

Answer:

3x+1y=35

Step-by-step explanation:

In the future try to search the answer up because thats how i found it

Answer:

3x +y=35

Step-by-step explanation:

Plato

2.-3(x-2) OS
(1 Point)
Enter your answer

Answers

Answer:

-3x+6

Step-by-step explanation:

Again, you multiply -3 times x and you get -3x, then you multiply -3 times -6 and since you are multiplying two negative numbers the result becomes positive so you get +6. Result = -3x+6

11x9/10 simplest form hellppp

Answers

Answer:

9.9 or 9 9/10

Step-by-step explanation:

9x11=99

99/10 = 9.9 or 9 9/10

Penn is using Shipping World’s international shipping rates to calculate the shipping cost for her packages. The company charges $30 plus $8 per pound for each package. Which graph models the cost, y, of shipping a package that weighs x pounds?

Answers

Answer:

[tex]y = 30 + 8x[/tex]

Step-by-step explanation:

Given

[tex]Base\ Amount = $30[/tex]

[tex]Additional = \$8[/tex] per pound

Required

Determine the graph

The cost (y) is calculated as thus:

[tex]y = Base\ Amount + Additional * x[/tex]

[tex]y = 30 + 8* x[/tex]

[tex]y = 30 + 8x[/tex]

See Attachment for graph

For 10 values denoted x, it is given that the mean equals7.4.
Find the sum of all values

Answers

Answer:

let's see what to do buddy....

Step-by-step explanation:

The mean of the 10 values denoted x equals 7.4

So we have :

[tex] \frac{x(1) + x(2) + x(3) + ... + x(10)}{10} = 7.4 \\ [/tex]

Multiply the sides of the equation by 10 :

[tex]10 \times \frac{x(1) + x(2) + x(3) + ... + x(10)}{10} = 7.4 \times 10 \\ [/tex]

After do that we have :

[tex]x(1) + x(2) + x(3) + ... + x(10) = 74 \\ [/tex]

Which means we have the sum of all values.

And we're done...

Thanks for watching.

Hope to be useful ♥️♥️♥️♥️♥️.

4x2 - 4x-8/2x +2
i just need someone to explain how to simplify it so i can graph it

Answers

Answer:

10-4x

Step-by-step explanation:

4×2-4x+2

8-4x+2 =10-4x

whats the decimal for 47.103

Answers

Answer:

that is a decimal

Step-by-step explanation:

PLEASE HELP I WILL MARK YOU BRAINLEIST​

Answers

[tex]\tt Step-by-step~explanation:[/tex]

We could see that the size of both images does not change, so it is not a dilation. The image is not mirrored either, so it is not a reflection. Finally, the image does not seem to change place that much from the preimage, so it should not be a translation, either. That means our answer is a rotation, because the image rotated about 180º.

[tex]\large\boxed{\tt Our~final~answer:~Rotation}[/tex]

Find the slope of the line above

Answers

Someone is answering good luck

Answer:

3/5

Step-by-step explanation:

Pick two points that are easy to read. pints that are easy to read are on the intersection of grid lines.

For example, pick (-2, 0) and (3, 3).

slope = rise/run

Rise is a vertical distance.

Run is a horizontal distance.

Start at (-2, 0). To go to (3, 3) by using only horizontal and vertical segments, go up 3 unit. Now go right 5 units.

The rise is 3. The runs is 5.

slope = rise/run = 3/5

Answer: 3/5

Gwen makes 30 cookies in 34 hour. At this rate, how many cookies could Gwen make in 3 hours?

Answers

Answer:

Step-by-step explanation:

30/34 is .8823 or .88 of a cookie

in 3 hours, she can make 2.647 or 2.7 of a cookie

The required number of cookies made in 3 hours is 2.64.

What is Unitary method ?

In order to solve a problem for two different values of a quantity, its unit value is first derived. This method is known as unitary method.

Given that,

The number of cookies made in 34 hour is 30.

Now, in order to calculate the number of cookies made in 3 hours unitary method can be used as follows,

In 34 hour the number of cookies = 30

In 1 hour the number of cookies = 30/34

Thus, in 3 hour the number of cookies = 30/34 × 3 = 2.64.

Hence, the number of cookies made with the given rate in 3 hours is 2.64.

To know more about unitary method click on,

https://brainly.com/question/28276953

#SPJ2

Jill and Erika made 4 gallons of lemonade for their lemonade stand. How many quarts did they make?
A .1 quart
B .16 quarts
C .20 quarts
D .5 quarts

Answers

Answer: B. 16 quarts

Work Shown:

1 gallon = 4 quarts .... think 4 quarters in a dollar

4*(1 gallon) = 4*(4 quarts) ... multiply both sides by 4

4 gallons = 16 quarts

If the function graphed is f(x), find f(1). Please hurry its urgent Thank you

A) -4
B) -1/4
C) 0
D) 4

Answers

I believe it would be negative -4 since y=-4 when x=1

Bonnie filled her car's gas tank. She put in 10 1/2 gallons and paid $15.36. Write the ratio in fractional form and determine the cost of gasoline per gallon

Answers

Answer:

The answer to the problem is $3.072

Whats the difference between Rational and irrational numbers?​

Answers

Answer:

Numbers that can be expressed as a ratio of two number (p/q form) are termed as a rational number. Numbers that cannot be expressed as a ratio of two numbers are termed as an irrational number.

Step-by-step explanation:

Bob loves M&Ms and nerds he was told he can by no more than 7 packs of candy which and inequality and illustrates this situation?​

Answers

Answer:

A

Step-by-step explanation: They can't be greater so automatically it's less than 7 or equal too

9) What is the sum and difference of the given functions?
f(x) = 3x2 + 2x
g(x)=-x?+ 4x
wer
tions
f + g = ?
f-g=?
Split
creen
A. $ +g =2x² + 6x
f-g=4x2 – 2x
B. f + g = 2x+6
s-g=4x2 - 2x
C. $+ g = 2x2 + 6
s-g= 4x-2
Split
Screen
A) Choice A
B) Choice B
C) Choice C
Unit
Save

Answers

Answer:

A

Step-by-step explanation:

if f(x)=3x^2+2x g(x)=‒x^2+4x

f+g=(3x^2+2x)+(‒x^2+4x)

=3x^2‒x^2+4x+2x

=2x^2+6x

f‒g=(3x^2+2x)‒(‒x^2+4x)

=3x^2+2x+x^2‒4x

=3x^2+x^2+2x‒4x

=4x^2‒2x

i hope my answer will be clear to you

You need a 55% alcohol solution. On hand, you have a 90 mL of a 20% alcohol mixture. You also have 70%
alcohol mixture. How much of the 70% mixture will you need to add to obtain the desired solution?

Answers

Answer:

o b

Step-by-step explanation:

a playground is rectangular with a length of 1/2 mi if the area of the playground is 5/8 square miles what is its width and put your answer as a fraction

Answers

Answer:

b = 5/4 miles

Step-by-step explanation:

Length of a rectangular playground, l = 1/2 miles

Area of the playground, A = 5/8 square miles

We need to find the width of the playground. We know that, the area of a rectangular shape is given by :

A = l×b, here b is the width of the playground.

[tex]b=\dfrac{A}{l}\\\\b=\dfrac{\dfrac{5}{8}}{\dfrac{1}{2}}\\\\b=\dfrac{5}{4}\ \text{miles}[/tex]

So, the width of the playground is 5/4 miles.

Help me pls what is 10,000 is 1/10 of

Answers

Answer:

1000

Step-by-step explanation:

What is the angle measure of angle b?
b
67°
A) 113°
C) 157°
B) 23°
D) 67°

Answers

Answer:

23 degrees

Step-by-step explanation:

You are given a right angle, which is 90 degrees. Part of the right angle is 67 degrees, so you do 90-67=23

Hope this helps ^^

Answer:

23 degrees

Step-by-step explanation:

This is because angle B and the angle that is 67 degrees are both apart of one right angle. We can solve this through a simple equation. 90 = x +67. Subtract 67 on both sides and you get X = 23 giving you the answer 23 degrees.

Puzzle #
1
A: :
THERE ARE 18 RED CRAYONS
AND 24 GREEN CRAYONS IN A
BASKET. WHAT IS THE RATIO OF
RED TO GREEN CRAYONS?
G:
A NEW COLOR OF GREEN
REQUIRES 5 PARTS YELLOW TO 4
PARTS BLUE IF THE PAINT MIXER
USED 30 GALLONS OF YELLOW.
HOW MANY GALLONS OF BLUE
WERE NEEDED?
3
AT YOUR NEW JOB AT THE COFFEE
SHOP, YOU SOLD 42 LARGE
COFFEES AND 54 SMALL COFFEES
WHAT WAS THE RATIO OF LARGE
TO SMALL COFFEES YOU SOLD?
UNDER A MICROSCOPE. YOU
COUNTED 48 AMOEBAS AND 56
PARAMECIUMS WHAT WAS THE
AMOEBA TO PARAMECIUM
RATIO?

Answers

answer

Step-by-step explanation:

I think that A is 3:4

Tickets to a basketball game can be ordered online for a set price per ticket plus a $5.50 service fee. The total cost in dollars for ordering 5 tickets is $108.00. Which linear function represents c, the total cost, when x tickets are ordered?
c(x) = 5.50 + 20.50x
c(x) = 5.50x + 20.50
c(x) = 5.50 + 21.60x
c(x) = 5.50x + 21.60

Answers

Answer:

5.50 + 20.50x

Step-by-step explanation:

hope its helps

What is the scale factor in the following algebraic representation of a dilation: (x,y) to (5x, 5y)

PLEASE HELP

Answers

Answer:

It would be dialating by a scale factor of 5 you can tell because you are multipllying (x,y) by 5

Mr. Keown has a penny design that is
modeled by the equation y=7x+2 where y is
the total number of pennies in the design
and x is the stage. How many pennies will
be in stage 7?

Answers

Answer: 51

Step-by-step explanation:

Step 1: Replace x in y = 7x + 2 where x = 7.

y = 7(7) + 2.

Step 2: Solve the equation.

y = 49 + 2

y = 51

A student scored 75 and 98 on her first two quizzes. Write and solve a compound inequality to find the possible values for a third quiz score that would give her an average between 85 and 90inclusive.

Answers

Answer:

i think 80

Step-by-step explanation:

Answer:

75+98/2

Step-by-step ex

The AVG with that problem is 86.5which is i between 85 and 90

What is the value of the expression (-2)^5

Answers

Answer:

-32

Step-by-step explanation:

-32 is the correct answer

Alessandra designed an experiment where subjects tasted water from four different cups and attempted to identify which cup contained bottled water. Each subject was given three cups that contained regular tap water and one cup that contained bottled water (the order was randomized). She wanted to test if the subjects could do better than simply guessing when identifying the bottled water.Her hypotheses were H0: p=0.25H vs.H a :p>0.25H,(where ppp is the true likelihood of these subjects identifying the bottled water).The experiment showed that 20 of the 60 subjects correctly identified the bottle water. Alessandra calculated that the statistic p=20, divided by, 60, 0.3 had an associated P-value of approximately 0.0680.What conclusion should be made using a significance level of α=0.05?A) Fail to reject H0B) Reject H0, and accept HaC) Accept H0​

Answers

Answer:

3434

Step-by-step explanation:

The conclusion that should be made on the question using a significance level of α=0.05 is; Option A; Fail to reject H₀

We are given the hypotheses;

Null Hypothesis; H₀; p = 0.25

Alternative hypothesis; Hₐ; p > 0.25

p^ = 0.3

p-value = 0.068

Now, we are told that the significance level is α = 0.05

      Now, the law in hypotheses testing is that when the p-value is less tan or equal to the significance level, we will reject the null hypothesis but when the p-value is greater than the significance value, we fail to reject the null hypothesis(H₀)

Now, in our question the p-value of 0.068 is greater than the significance level of 0.05 and thus we will fail to reject the null hypothesis.

Read more at; https://brainly.com/question/17128186

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