A simple random sample of 25 items from a normally distributed population resulted in a sample mean of 28 and a standard deviation of 7.5. Construct a 95% confidence interval for the population mean.

Answers

Answer 1

Answer:

CI = 28 ± 3.09

Step-by-step explanation:

The sample size, n = 25

The sample mean, m = 28

Standard deviation, s = 7.5

Confidence interval is given as:

CI = Sample mean ± margin of error

We want to find 95% confidence level:

First, let us find the margin of error:

Margin of error = Critical value * standard error

To find the critical value, we need some parameters:

Standard error = [tex]s / \sqrt{n}[/tex]

=> [tex]SE = 7.5 / \sqrt{25}= 7.5 = 5 = 1.5[/tex]

The alpha value, ∝ = 1 - (confidence level / 100) = 1 - 95/100 = 1 - 0.95 = 0.05

Critical probability, p, is given as:

p = 1 - ∝/2 = 1 - 0.05/2 = 1 - 0.025 = 0.975

Now we need the degree of freedom:

df = n - 1 = 25 - 1 = 24

Therefore, the critical value is 2.06 (you can use an online t value calculator).

=> Margin of error = 2.06 * 1.5 = 3.09

Therefore, the confidence interval for the population mean is:

CI = 28 ± 3.09


Related Questions

-3.42, 10.26, -30.78, 92.34, ___,... what is the next number

Answers

Answer:

-277.02

Step-by-step explanation:

Given series:

-3.42, 10.26, -30.78, 92.34,...

We can see the series is a GP with common ratio of -3, as:

10.26/-3.42= -30.78/10.26= 92.34/-30.78= -3

So the next term will be:

92.34 × (-3)= -277.02

the length of a rectangle is twice its width, the perimeter of it is 36cm. what is the are of it

Answers

Answer: 72 cm²

Step-by-step explanation: lets take the width as x and length as 2x as length is twice the width= perimeter of rectangle is 2*(l+b)=36cm

So, 2×(2x+x)=36cm

2×3x=36cm

6x=36cm

X=36/6:6cm( width, since width was taken as x)

Length= 2x: 2×6=12cm

So area of the rectangle is( l*b):

12×6= 72cm²

Help please solve this

Answers

RU is a diameter, so the two equations make half a circle which is 180 degrees.

24x+5 + 10x+5 = 180

Combine like terms:

34x + 10 = 180

Subtract 10 from both sides:

34x = 170

Divide both sides by 34

X= 5

RS= UV

RS = 10x +5

Replace x with 5

RS = 10(5) + 5 = 55

Answers:

X = 5

RS = 55

A page in an average newspaper has 8 columns of print. Each column consists of 160 lines and each line averages 6 words. What's the average number of words on a full page?

Answers

Answer:

7,680

Step-by-step explanation:

A page has 8 columnsEach column consists of 160 lines.Each line averages 6 words.

The average number of words on a full page

=Number of columns X Number of Lines X Number of words per line

=8 X 160 X 6

=7680

The average number of words on a full page is 7,680.


NEED MATH HELP NOW. Need help find the vertex and y intercept. Please show work.

Answers

Answer:

Vertex:   ( 1 ,  9 )

Y-intercept:   ( 0 ,  8 )

Step-by-step explanation:

y = - (x+2) (x-4)

y = -x² + 2x + 8

Find the vertex.

x = -b/2a

x = -2/2(-1)

x = -2/-2

x = 1

y = -(1)² + 2(1) + 8

y = -1 + 2 + 8

y = 9

Find the y-intercept.

Put x as 0.

y = -(0)² + 2(0) + 8

y = 8

Which table represents a linear function

Answers

Answer:

The first photo

Step-by-step explanation:

Its a i think

help help meeeee pls

Answers

28/5, you cross multiply so 4/5=y/7 would become 5y=28 then you solve for y from there which becomes 28/5

−6(x+7)=−4x−2 how many solutions

Answers

Answer: There is one solution, -20

Step-by-step explanation:

[tex]-6(x+7)=-4x-2\\\\Distribute\\\\-6x-42=-4x-2\\\\Add(6x)\\\\-42=2x-2\\\\Add(2)\\\\-40=2x\\\\x=-20[/tex]

There is one solution, -20

Hope it helps <3

Answer:

Only one solution

Step-by-step explanation:

Solution,

[tex] - 6(x + 7) = - 4x - 2[/tex]

Distribute -6 through the parentheses

[tex] - 6x - 42 = - 4x - 2[/tex]

Move variable to L.H.S and change its sign

[tex] - 6x + 4x - 42 = - 2[/tex]

Move constant to R.H.S and change its sign

[tex] - 6x + 4x = - 2 + 42[/tex]

Collect like terms

[tex] - 2x = - 2 + 42[/tex]

Calculate the sum

[tex] - 2 x = 40[/tex]

Divide both sides of the equation by - 2

[tex] \frac{ - 2x}{ - 2} = \frac{40}{ - 2} [/tex]

Calculate

[tex] x = - 20[/tex]

Hope this helps..

Good luck on your assignment..

a line has a gradient of 4 and passes through the post (1,7). what is the equation?

Answers

Answer:

y = 4x + 3

Step-by-step explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Here m = 4, thus

y = 4x + c ← is the partial equation

To find c substitute (1, 7) into the partial equation

7 = 4 + c ⇒ c = 7 - 4 = 3

y = 4x + 3 ← equation of line

Answer:

The equation is y = 4x+3

Step-by-step explanation:

The slope intercept form of a line is

y = mx+b where m is the slope and b is the y intercept

y = 4x + b

Substitute the x and y value into the equation

7 = 4(1)+b

7 = 4+b

Subtract 4

7-4 =b

3=b

The equation is y = 4x+3

A soccer player gets 2 points for a goal and 1 point for an assist. If the combined number of goals and assists that a player has is 24, and the total number of points that the player has is 42, which system of equations can be used to determine the number of goals and assists the player has? Assume g represents the number of goals and a represents the number of assists.

A)g + a = 24. g + 2 a = 42.
B)g + a = 24. 2 g + a = 42.
C)g + a = 42. g + 2 a = 24.
D)g + a = 42. 2 g + a = 24.

Answers

Answer:

B

Step-by-step explanation:

The soccer player has g goals and a assists.

For every goal, he/she gets 2 points and for every assist, he/she earns 1 point. This means that if we multiply g by 2, we get the number of points the player receives from g goals and if we multiply a by 1, we get the number of points the player receives from a assists.

And, that total number of points is equal to 42, so we can write:

2 * g + 1 * a = 42

2g + a = 42

Now, we understand that g and a are the number of goals and assists the player has made, and we also know that the total number of such kicks is 24, so we can write:

g + a = 24

Thus, our system is:

g + a = 24

2g + a = 42

The answer is B.

~ an aesthetics lover

Answer:

The correct answer is B. g + a = 24. 2 g + a = 42

11. Three men can build a wall in 10 hours. How
many men would be needed to build the wall in
7 hours?

Answers

Answer:

Man-hours to build the wall: 3 * 10 = 30

:

let m = no. of men required to do it 7.5 hrs

7.5m = 30

m = [tex]\frac{30}{7.5}[/tex]

m = 4 men to build it in 7.5 hrs

Step-by-step explanation:

15 POINTS!!!!! suppose f(x)=x find the graph of f(x+2) please include what the graph would look like

Answers

Answer:

The graph f(x+2) would make the graph go left by 2 units.

Step-by-step explanation:

Using graph transformations, adding two would make the graph go left 2 and subtracting would make it go right 2

A herd of bison currently has 55 members. Based on the available resources,
biologists estimate that the size of the herd will increase at a rate of 6% per
year. Which of the following graphs models this relationship, if the x-axis
represents years and the y-axis represents number of bison?

Answers

The equation y is equal to 55(1.06) to power x models the relationship between the x-axis which represents years and the y-axis, which represents number of bison.

What is an exponential function?

It is defined as the function that rapidly increases and the value of the exponential function is always a positive. It denotes with exponent y = a^x

where a is a constant and a>1

We have:

A herd of bison currently has 55 members, and biologists estimate that the size of the herd will increase at a rate of 6% per year.

We can model this relationship:

[tex]\rm y = 55(1+0.06)^x\\\\\rm y = 55(1.06)^x[/tex]

Thus, the equation y is equal to 55(1.06) to power x models the relationship between the x-axis which represents years and the y-axis, which represents number of bison.

Learn more about the exponential function here:

brainly.com/question/11487261

#SPJ2

. Francisco states the following: When two or more factors are multiplied and they have the same sign, the product is positive. List two examples that support Francisco's statement. Show their products.

Your answer

6B. List an example that refutes Fracisco's statement. Show its product. Explain why it refutes his statement.

Your answer

6C. How could Francisco rewrite his statement so it is always true?

pls Help me​

Answers

Answer:

6A) i) 5 and 3 product is 15

ii) (-5) and (-3) product is 15

6B. The product of 5·i and 3·i is -15

6C. When two or more real factors are multiplied and they have the same sign, the product is positive

Step-by-step explanation:

6A. To examples that support Francisco's statement are;

Given the factors that have the same sign;

i) 5 and 3 both positive

ii) (-5) and (-3) both negative

The products of each of the two factors are therefore;

5 × 3 = 15 (Positive product)

(-5) × (-3) = 15 (Positive product)

6B. An example that refutes Francisco's claim is the product of two imaginary numbers 5·i and 3·i where i = √(-1) as follows;

5·i × 3·i = 15·i² = 15×i×i = 15 × √(-1) ×√(-1) = 15×(√(-1))² = 15 × (-1) = -15

Therefore;

5·i × 3·i = -15 which is a negative number and therefore refutes Francisco's claim

6C. Francisco could rewrite his statement as follows;

When two or more real factors are multiplied and they have the same sign, the product is positive

To make it always true.

Here were 87 sunflowers at the flower shop in the morning. There were 56 sunflowers left at the end of the day. How many sunflowers were sold? Explain a way to solve the problem.

Answers

Answer:

31

Step-by-step explanation:

We just have to calculate 87 - 56 which is 31 so the answer is 31 sunflowers.

Answer:

31

Step-by-step explanation:

Since we know that we started with a higher number than we ended with, it is obvious that this is a subtraction problem. Then, we simply have to find the difference by subtracting 87 by 56 (87 - 56 = x). After the calculation, we see that the answer is 31 (87 - 56 = 31).

Sam bakes a variety of biscuits. 1/3
are peanut, 12 are raisin and the
remaining 12 were oat. How many
biscuits are baked?

Answers

Answer: 36

Step-by-step explanation:

Let the no. of biscuits be x

Peanuts will be 1/3x

So,

1/3x + 12 + 12 = x

1/3x + 24 = x

x + 72 = 3x

x-3x = -72

x = 72/2 = 36

Peanut biscuits will be 1/3 * 36 = 12

Total no. of biscuits baked were 12+12+12 = 36

) We throw 9 identical balls into 7 bins. How many different ways are there to distribute these 9 balls among the 7 bins such that no bin is empty? Assume the bins are distinguishable (e.g., numbered 1 through 7).

Answers

Answer:

28 ways

Step-by-step explanation:

After placing 1 ball in each of the seven bins, there are two balls left.

If we place both balls in a single bin, there are 7 different ways to place the balls (place both on bins 1 through 7).

If we place each of the remaining balls in a different bin, the number of ways to place the balls is:

[tex]n_2=\frac{7!}{(7-2)!2!}=7*3=21[/tex]

The total number of ways to distribute those balls is 21 + 7 = 28 ways.

In the diagram, the measure of angle 6 is 98°. what is the measure of angle 7?

Answers

Answer:

7∠82°

Step-by-step explanation:

Well angle 6 and 7 are complementary angles, meaning they both add up to 180°.

So we do 180 - 98 which is 82°.

Answer: The measure of angle 7 is 82 degrees.

Step-by-step explanation:

Angle  6 and 7  lies on a straight line so they will add up to 180 degrees.

So if Angle 6 is 98 degrees then an a number plus 98 has to equal 180.

so we could generate an equation as x + 98 = 180  

x + 98 = 180 solve for x

 -98      -98

x= 82  

Classify the following triangle. Check all that apply.

Answers

Answer:

Isosceles, obtuse triangle

Step-by-step explanation:

The triangle is isosceles since there are equal acute-angles which therefore prove two equal sides.

The triangle is obtuse because it consists of one obtuse angle which is 98 and is greater than 90 degrees.

Hope this helps!!! PLZ MARK BRAINLIEST!!!

What is the period of the function y= 3/2 cot(3/5x) +5?

A. Pi/5 units

B. 3pi/5 units

C. 2pi/3

D. 5pi/3

Answers

Answer:

D; 5pi/3 units

Step-by-step explanation:

Here, we want to find the period of the function;

y = 3/2 cot (3/5x) + 5

By definition, the period of a function is the interval between two matching points in the function.

Let’s say it is the distance between two peaks, crests, etc on a function.

To find the value of the period. We shall standardize the function.

What this means is that we shall be writing the function in the standard form.

The standard form is as follows;

f(x) = A trig(Bx -C) + D

Where trig refers to the accompanying trigonometric function in question.

Comparing this standard form with our question, we can see that;

A is 3/2

B is 3/5

C is 0

D is 5

Now for cot and tan functions, we shall need to divide pi by the absolute value of B

Thus we have; pi divided by 3/5 which gives 5pi/3 units

Answer:

D. 5pi/3, period is the distance between the repetition of a function.

Step-by-step explanation:

Find the value of b. Round your answer to the nearest tenth.


The figure shows acute triangle A B C. The measure of angle B is 40 degrees. The length of side A B is 10. The length of side B C is 12. The length of side C A is b.

Answers

Answer:

Side CA = 7.8

Step-by-step explanation:

Given:

Acute angled [tex]\triangle ABC[/tex].

[tex]\angle B =40^\circ[/tex]

AB = 10

BC = 12

We can use cosine rule here to find the side AC = b

Formula for cosine rule:

[tex]cos B = \dfrac{a^{2}+c^{2}-b^{2}}{2ac}[/tex]

Where  

a is the side opposite to [tex]\angle A[/tex]

b is the side opposite to [tex]\angle B[/tex]

c is the side opposite to [tex]\angle C[/tex]

[tex]cos 40 = \dfrac{12^{2}+10^{2}-b^{2}}{2\times 12\times 10}\\\Rightarrow cos 40 = \dfrac{144+100-b^{2}}{240}\\\Rightarrow 0.77 = \dfrac{244-b^{2}}{240}\\\Rightarrow 244-b^{2} = 0.77 \times 240\\\Rightarrow 244-b^{2} = 183.85\\\Rightarrow 244-183.85 = b^{2}\\\Rightarrow b^2 = 60.15\\\Rightarrow b = 7.76[/tex]

To the nearest tenth b = 7.8

I really need help with this question, it's confusing. It's geometry btw

Answers

Answer:

Two regular nonagons and nine congruent rectangle

Step-by-step explanation:

Two regular nonegon=on the surface and base..

Nine congruent rectangle=look at beside it will be look like 9 rectangle.. I hope it will be right.

HELP ME PLEASE HELP ME HELP ME PLEASE

Answers

Answer:

    no, because the remainder is 126

Step-by-step explanation:

if x+3 is a factor, then -3 is a root of expression, and the remainder would be 0

calculating remainder:

[tex]-3(-3)^3+6(-3)^2+6(-3)+9=-3\cdot(-27)+6\cdot9-18+9=\\\\=81+54-9=126[/tex]

cube of -1/2 is equal to-----------. i need urgent please.I will mark brainest

Answers

Answer:

-1/8

Step-by-step explanation:

(-1/2)(-1/2)(-1/2)=-1/8

Answer:

[tex] \frac{ - 1}{8} [/tex]

solution,

[tex] (\frac{ - 1}{2} ) ^{3} \\ = \frac{( { - 1)}^{3} }{( {2}^{3} )} \\ = \frac{ - 1 \times ( - 1) \times ( - 1)}{2 \times 2 \times 2} \\ = - \frac{ 1}{8} [/tex]

hope this helps...

Good luck on your assignment

someone help me asap please/math 10

Answers

Answer:

Step-by-step explanation:

4.  a) tan x=17/12=1.416

       x=54.8≈55

b)sin  b=78/132=0.59

  b=36.2≈36

cos 28=x/82

x=82*cos 28=82*0.9=73.8

In a sale normal prices are reduced by 10% Angelina bought a pair of shoes in the sale for £54 what was the original pricee of the shoes?

Answers

Answer:

£60

Step-by-step explanation:

Given that

The cost after reduction  = £54

So, 90% = £54

We have to find 100%

To do so, find 10% and ,multiply that by 10

90% = £54

10% = 54/9 = £6

1005 = 6x10 = £60

Hope this helps,.

Please mark brainiest

A group of 4 friends have a bag of 49 sweets. They divide the sweets equally between them. a) How many sweets does each friend get? b) How many sweets are left over

Answers

Answer:

a) Each friend gets 12 sweets

b) There is 1 sweet left

Step-by-step explanation:

When you divide 49 by 4 you will get 12 with a remainder 1.

49 ÷ 4 = 12 R1

The remainder is the left over while the total result is how much each friend gets.

Answer:

A) 12

B) 1

Step-by-step explanation:

49 cannot be divided equally among the 4 friends but 48 can be divided.

A) So,

48/4 = 12 sweets

Each friend gets 12 sweets

B) 1 sweet is left

simplify the expression (x - 2y) + (3x + 4y)

Answers

Simplifying the expression (x - 2y) + (3x + 4y).

Work:

(x - 2y) + (3x + 4y)

Combine like terms.

x + 3x = 4x

-2y + 4y = 2y

Reform the expression.

4x + 2y

Simplified Expression: 4x + 2y.

4.8x10^-3 as an ordinary number

Answers

Answer:

0.008.

Step-by-step explanation:

10^-3 basically tells you to move the decimal point to the left by three digits.

Right now, you have 8. If the decimal point were to move left by three digits, you can visualize 8 as 0008. Move left by three digits, and you get 0.008.

Hope this kind of helps!

Answer:

0.008.

hope this helps :)

When x= 12, y= 144. (a) Express y in terms of x. (b) Find the value of y when x= 7.

Answers

Answer:

see explanation

Step-by-step explanation:

Given x = 12, y = 144

We can see that y is 12 times the value of x, thus

(a)

y = 12x

(b)

when x = 7, then

y = 12 × 7 = 84

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