The lengths of text messages are normally distributed with a population standard deviation of 6 characters and an unknown population mean. If a random sample of 27 text messages is taken and results in a sample mean of 29 characters, find a 95% confidence interval for the population mean. Round your answers to two decimal places.

Answer:

Step-by-step explanation:

Hello,

We just need to apply the formula using the discriminant

[tex]-6x^2-2x+1=0\\\\\Delta = b^2-4ac = (-2)^2-*4(-6)*1=4+24=28[/tex]

so we have two distinct real solutions

[tex]x_1=\dfrac{2+\sqrt{28}}{2*(-6)}=\dfrac{2+2\sqrt{7}}{2*(-6)}=-\dfrac{\sqrt{7}+1}{6} \\\\ and \\\\x_2=\dfrac{\sqrt{7}-1}{6}[/tex]

Hope this helps

Answer:

( x, y ) = ( -20, 20 )

Step-by-step explanation:

Given data

Y = y(x)

3x + 2y = 20 ---------- equation 1

2x + 3y = 20 ---------- equation 2

find (x, y )

solving equation 1 and equation 2

3x + 2y = 20 * 2 = 6x + 2y = 40 --------- EQUATION 3

2x + 3y = 20 * 3 =  6x + 3y = 60 --------- EQUATION 4

cancelling out ( x )

Add both equation 3 and equation 4

5y = 100.  hence  y = 100/5 = 20

back to equation equation 2

2x + 3(20) = 20

2x = - 40

x = -20

attached is the graph  to check the answer

Answer:

The x-values of the inflection points of the curve are x = -52 and x = 52.

Step-by-step explanation:

Suppose we have a normal curve with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex]

The x-values of the inflection points of the curve are [tex]x = \mu - \sigma[/tex] and [tex]x = \mu + \sigma[/tex]

x ~ N(0, 52)

This means that [tex]\mu = 0, \sigma = 52[/tex]

So

[tex]x = 0 - 52 = -52[/tex]

[tex]x = 0 + 52 = 52[/tex]

The x-values of the inflection points of the curve are x = -52 and x = 52.

Answer:  see below

Step-by-step explanation:

Inverse is when you swap the x's and y's.

The Slope-Intercept form is [tex]y=\dfrac{1}{5}x-\dfrac{3}{5}[/tex]    which isn't convenient to graph.

So take the points from the original equation (-1, -2) & (0, 3) and switch the x's and y's to get the points (-2, -1) & (3, 0).

Draw a line through points (-2, -1) and (3, 0) to sketch the graph of the inverse.

Answer:

Tublu has more than enough paint to cover the tank surface in one layer coating

Step-by-step explanation:

Height of the cylinder = 1.4 m

diameter of the cylinder = 1.1 m

total volume of paint available = 2 litres

It takes 250 ml to cover 1 m^2 of the tank body

Since only the body is to be painted, we find the perimeter of the circle formed by the body of the tank.

perimeter of the circle formed by the body of the  tank = [tex]\pi d[/tex]

==> 3.142 x 1.1 = 3.456 m

This perimeter, if spread out, will form a rectangle with a height of 1.4 m from the base.

The area of the rectangle that will be formed =  (perimeter of the cylinder body) x ( height of the cylinder)

==> 3.456 x 1.4 = 4.838 m^2

This is the area that needs to be painted.

Converting the paint volume,

250 ml = 0.25 litres

To paint the above calculated are, we will need 4.838 x 0.25 = 1.21 litres of paint, (of course, excluding the base)

The volume of paint available = 2 litres

volume of paint needed = 1.21 litres

Tublu has more than enough paint to cover the tank surface in one layer coating

Answer:

A. y=-1/4x

Step-by-step explanation:

We have the information 3y=12x-9, the lines are perpendicular, and the new line passes through (-4,1). First, you want to put the original equation into slope intercept form by isolating the y, to do this we need to divide everything by 3 to get y=4x-3. The slopes of perpendicular lines are negative reciprocals so you need to find the negative reciprocal of 4, so flip it to 1/4 and multiply by -1, we get the slope of the new line as -1/4. So far we have the equation y=-1/4x+b. We are given a point on the line, (-4,1), we can plug these into the equation as x and y to solve for the y-intercept, b. You set it up as 1=-1/4(-4)+b. First you multiply to get 1=1+b, then you subtract 1 from both sides to isolate the variable and you get b=0. Then you can use b to complete your equation with y=-1/4x, or letter A.

Answer: 132

Step-by-step explanation: To solve this equation we know that x is greater than 81 unless the equation would not make sense. 81 + 51 = 132

Answer: x=132

Step-by-step explanation: Add 51 to 81, as positive 51 is the inverse of -51. You need to get the x alone. Therefore, 51+81=132 and x=132.

Answer:

the answer is C.

Step-by-step explanation:

64 ÷ 8 = 8

Answer:

c- 8cm squared

Step-by-step explanation:

plato

Answer: 8y⁸

Step-by-step explanation:

To find the square root of the expression, you want to find the square root of each term.

The square root of 64 is 8. You can write y¹⁶ as (y⁸)². We can pull out this 2 from the square root because it cancels out with the square root. Therefore, the answer is 8y⁸.

Problem 1

Explanation: Circle or highlight the angles 10 and 15. They are alternate interior angles with line d being the transversal cut. It might help to try to erase line c to picture the transversal line d better. With d as the transversal, and angles 10 and 15 congruent, this must mean lines a and b are parallel by the alternate interior angle theorem converse.

==============================================

Problem 2

Explanation: The angles at the top are 32 degrees, 90 degrees, and x degrees which is the missing unmarked angle at the top (all three angles are below line m). The three angles must add to 180 to form a straight angle

32+90+x = 180

x+122 = 180

x = 180-122

x = 58

The missing angle is 58 degrees. This is very close to 57 degrees at the bottom. Though we do not have an exact match. This means lines m and n are not parallel. The alternate interior angles must be congruent for m and n to be parallel, as stated earlier in problem 1.

Answer:

[tex]\dfrac{1}{7}[/tex]

Step-by-step explanation:

There are 7 days in a week.

For the first person, we select one day out of the 7 days. The first person has 7 options out of the 7 days.

Let Event A be the event that the first person was born on a day of the week.

Therefore:

[tex]P(A)=\dfrac{7}{7}=1[/tex]

The second person has to be born on the same day as the first person. Therefore, the second person has 1 out of 7 days to choose from.

Let Event B be the event that the second person was born.

Therefore, the probability that the second person was born on the same day as the first person:

[tex]P(B|A)=\dfrac{1}{7}[/tex]

By the definition of Conditional Probability

[tex]P(B|A)=\dfrac{P(B \cap A)}{P(A)} \\$Therefore:\\P(B \cap A)=P(B|A)P(A)[/tex]

The probability that both were born on the same day is:

[tex]P(B \cap A)=P(B|A)P(A) = \dfrac{1}{7} X 1 \\\\= \dfrac{1}{7}[/tex]

Answer:

z = 10

Step-by-step explanation:

The value of the z-statistic is given by:

[tex]z = \frac{X - \mu}{s}[/tex]

In which:

X is the measured value.

[tex]\mu[/tex] is the expected value.

[tex]s = \frac{\sigma}{\sqrt{n}}[/tex] is the standard deviation of the sample. [tex]\sigma[/tex] is the standard deviation of the population.

In this question:

The mean length was 2.9 inches, and the population standard deviation is 0.1 inch.

This means that [tex]\mu = 2.9, \sigma = 0.1[/tex]

Random sample of 100 screws.

This means that n = 100.

To see if the batch of screws has a significantly different mean length from 3 inches, what would the value of the z-test statistic be?

3 inches, so [tex]X = 3[/tex]

[tex]s = \frac{0.1}{\sqrt{100}} = 0.01[/tex]

[tex]z = \frac{X - \mu}{s}[/tex]

[tex]z = \frac{3 - 2.9}{0.01}[/tex]

[tex]z = 10[/tex]

Answer:

-10

Step-by-step explanation:

If we first note the denominator of fraction numerator sigma over denominator square root of n end fraction equals fraction numerator 0.1 over denominator square root of 100 end fraction equals fraction numerator begin display style 0.1 end style over denominator 10 end fraction equals 0.01

Then, getting the z-score we can note it is z equals fraction numerator x with bar on top minus mu over denominator begin display style 0.01 end style end fraction equals fraction numerator 2.9 minus 3 over denominator 0.01 end fraction equals negative 10

This tells us that 2.9 is 10 standard deviations below the value of 3, which is extremely far away.

Answer:

The correct answer to the following question will be "60 students".

Step-by-step explanation:

Marta will be taking a sampling frame from some kind of 600 student group.

Mean,

N = 60  

Although the sampling method could perhaps consist of the following components 10% of the population,

⇒  [tex]600\times 10 \ percent[/tex]

⇒  [tex]60[/tex]

In order to view these findings as autonomous, 60 students would then have to analyze Marta lacking replacements.

Marta have to sample 60 students without replacement to treat the observations as independent.  

Given,

Marta is going to take a sample from a population of 600 students.

We have to find the no. of students Marta have to sample without replacement.

The 10% condition states that sample sizes should be no more than 10% of the population. Normally, Bernoulli trials are independent, but it's okay to violate that rule as long as the sample size is less than 10% of the population.

So,

[tex]N=10\% \ of \ 600[/tex]

[tex]N=\frac{10}{100} \times600[/tex]

[tex]N=60[/tex]

Hence, Marta have to sample 60 students without replacement to treat the observations as independent.

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Answer:

Option (A).

Step-by-step explanation:

The function f(x) = x² + 4 is defined over the interval (-2, 2)

Total number of equal parts between this interval = 5

If the interval is divided into n equal parts, height of the right endpoint of each rectangle = [tex]\frac{5}{n}[/tex]

Height of the endpoint of the k rectangles = [tex]k.\frac{5}{n}[/tex]

Therefore, height of the endpoint of the kth rectangle = Height of first rectangle + height of k rectangles

= -2 + [tex]k.\frac{5}{n}[/tex]

Option (A). will be the answer.

The height of the right endpoint of the kth rectangle h = -2 + k (5/n)

The height is a vertical distance between two points. In the case of the triangle, the height will be the distance between the base and the top vertex of the triangle.

The function f(x) = x² + 4 is defined over the interval) (-2, 2 )

Total number of equal parts between this interval = 5

If the interval is divided into n equal parts, the height of the right endpoint of each rectangle = (5/n)

Height of the endpoint of the k rectangles = k (5/n)

The height of the endpoint of the kth rectangle:-

= Height of first rectangle + height of k rectangles

= -2   +  k (  5/n )

Therefore the height of the right endpoint of the kth rectangle h = -2 + k (5/n)

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Answer:

7x+7 is obviously divisible by 7.

put in any value high enough and you can find the two three digit numbers.

Step-by-step explanation:

Two three-digit numbers divisible by 7 are 98 and 105.

Two three-digit numbers divisible by 7 are 98 and 105.To create an expression that is divisible by 7, we can use the property that the difference between two numbers is divisible by 7 if the numbers themselves are divisible by 7.

Let's represent a three-digit number divisible by 7 as "7k" where k is an integer. To find two three-digit numbers divisible by 7, we can use the following expression:

7k - 7

For example, if we substitute k = 15, we get:

7(15) - 7 = 105 - 7 = 98

So, the first three-digit number divisible by 7 is 98.

Similarly, for the second three-digit number, let's substitute k = 16:

7(16) - 7 = 112 - 7 = 105

Therefore, the two three-digit numbers divisible by 7 are 98 and 105.

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Answer:

Step-by-step explanation:

According to the central limit theorem, if independent random samples of size n are repeatedly taken from any population and n is large, the distribution of the sample means will approach a normal distribution. The size of n should be greater than or equal to 30. Given n = 100 for both scenarios, we would apply the formula,

z = (x - µ)/(σ/√n)

a) x is a random variable representing the salaries of accounting graduates. We want to determine P( x > 52000)

From the information given

µ = 50402

σ = 6000

z = (52000 - 50402)/(6000/√100) = 2.66

Looking at the normal distribution table, the probability corresponding to the z score is 0.9961

b) x is a random variable representing the salaries of finance graduates. We want to determine P(x > 52000)

From the information given

µ = 49703

σ = 10000

z = (52000 - 49703)/(10000/√100) = 2.3

Looking at the normal distribution table, the probability corresponding to the z score is 0.9893

c) The probabilities of either jobs paying that amount is high and very close.

Answer:

4.7

Step-by-step explanation:

Given :

initial mean length =4.1  minutes.

Final mean length =5.3 minutes

The mid point of the given interval can be determined by the

[tex]Midpoint \ = \frac{Initial\ Mean\ length\ +Final\ Mean\ length }{2} \\Midpoint \ = \frac{4.1\ +\ 5.3\ }{2} \\Midpoint \ = \frac{9.4 }{2} \\Midpoint \ =4.7\\[/tex]

Therefore 4.7 is the midpoint

Answer:

245 might be the answer

Step-by-step explanation:

(7*7*10)/2

Hey there! :)

Answer:

10 miles.

Step-by-step explanation:

To solve for the diagonal side, we can simply visualize the sides of the rectangle as sides of a right triangle with the diagonal being the hypotenuse.

We can use the Pythagorean Theorem (a² + b² = c²), where:

a = length of short leg

b = length of long leg

c = length of the diagonal

Solve:

c² = a² + b²

c² = 6² + 8²

c² = 36 + 64

c² = 100

c = 10 miles. This is the length of the pedestrian route.

Answer:

Solution,

Hypotenuse (h) = R

Perpendicular (p) = 8 miles

Base (b) = 6 miles

Now,

Using Pythagoras theorem:

[tex] {h}^{2} = {p}^{2} + {b}^{2} [/tex]

Plugging the values:

[tex] {r}^{2} = {(8)}^{2} + {(6)}^{2} [/tex]

Calculate:

[tex] {r}^{2} = 64 + 36[/tex]

[tex] {r}^{2} = 100[/tex]

[tex]r = \sqrt{100} [/tex]

[tex]r = 10 \: miles[/tex]

Length of route = 10 miles

Hope this helps...

Good luck on your assignment...

Answer:

[tex]\frac{16}{9}[/tex].

Step-by-step explanation:

[tex](2^8*3^{-5}*6^0)^{-2}*(\frac{3^{-2}}{2^3})^4*2^{28}\\ (2^8*\frac{1}{3^5}*1)^{-2}*\frac{\frac{1}{3^8} }{\frac{2^{12}}{1} }*2^{28} \\ (\frac{2^8}{3^5})^{-2} * \frac{1}{2^8*3^{12}} *2^{28}\\ \frac{1}{\frac{2^8*2}{3^{5*2}} } * \frac{1}{2^8*3^{12}} *2^{28}\\ \frac{\frac{1}{1} }{\frac{2^{16}}{3^{10}} } * \frac{1}{2^8*3^{12}} *2^{28}\\ \frac{3^{10}}{2^{16}} * \frac{1}{2^8*3^{12}} *2^{28}\\ \frac{2^{28}}{2^{24}*3^2} = \frac{2^4}{3^2}=\frac{16}{9}[/tex]

Answer:

4 = 4

Step-by-step explanation:

=> 2x = 4

Putting x = 2

=> 2(2) = 4

=> 4 = 4

Answer:

Solution,

X= 2

Now,

2x=4

plugging the value of X,

2*2= 4

4 = 4 ( hence it is true)

Answer:

Step-by-step explanation:

As you show, the weight differences are different for the same week differences, so the table is not linear. A graph (attached) can also show you the table is not linear.

__

The highest rate of weight loss shown in the table is 7 lbs in 3 weeks, or 4 2/3 pounds in 2 weeks. The lowest rate of weight loss shown in the table is 5 lbs in 3 weeks, or 3 1/3 pounds in 2 weeks. Based on the rates shown in the table, we might expect the starting weight to be between 3 1/3 and 4 2/3 pounds more than the first table value:

  Week 0 weight: between 184 1/3 and 185 2/3 lbs, estimated.

_____

A "line of best fit" for the data has a y-intercept of about 185 pounds, which is the midpoint between our two estimates above.

Answer:

Hello!

~~~~~~~~~~~~~~~``

Simplifying

2x + 3y = 45

Solving

2x + 3y = 45

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-3y' to each side of the equation.

2x + 3y + -3y = 45 + -3y

Combine like terms: 3y + -3y = 0

2x + 0 = 45 + -3y

2x = 45 + -3y

Divide each side by '2'.

x = 22.5 + -1.5y

Simplifying

x = 22.5 + -1.5y

Hope this helped you! Brainliest would be nice.

Question:

A cinema can hold 270 people at one performance 5/9 of the seats were occupied of the occupied seats 40% we occupied by concessionary ticket holders.

What is the number of seats occupied by concessionary ticket holders?.

Answer:

60 seats

Step-by-step explanation:

Given

Number of seats = 270

Occupied Seats = 5/9

Concessionary ticket holders = 40% of occupied Seats

Required

The number of seats occupied by concessionary ticket holders

First the number of occupied seat has to be calculated.

[tex]Occupied\ Seats = \frac{5}{9} * 270[/tex]

[tex]Occupied\ Seats = \frac{1350}{9}[/tex]

[tex]Occupied\ Seats = 150[/tex]

Next is to determine the number of seats occupied by concessionary ticket holders.

[tex]Number = 40\%\ of\ occupied\ seats[/tex]

[tex]Number = 40\%\ of\ 150[/tex]

Convert percentage to decimal

[tex]Number = 0.4 * 150[/tex]

[tex]Number = 60[/tex]

Hence, 60 seats were occupied by concessionary ticket holders.

Answer:

5x + 10 = 25

Subtract 10 on each side to make x alone

5x = 15

divide by 5 on each side

x=3 so x=3

3x + 12 = 48

48-12=36

3x=36

divide by 3

x=12

4x + 8 = 16

4x = 8

x=2

2x + 15=25

2x=10

x=5

5x + 20 = 50

5x=30

x=6

hope this helps

1. 3

2.12

3.2

4.5

5.6

Step-by-step explanation:

Answer:

Step by step explanation

First:

Solution,

1. 5x + 10 = 25

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

5x = 25 - 10

Calculate the difference

5x = 15

Divide both sides by 5

5x/5 = 15/5

calculate

X = 3

2. 3x + 12 = 48

or, 3x = 48 - 12

or, 3x = 36

or, 3x/x = 36/3

x = 12

3. 4x + 8 = 16

or, 4x = 16 - 8

or, 4x = 8

or, 4x/x = 8/4

x = 2

4. 2x + 15 = 25

or, 2x = 25 - 15

or, 2x = 10

or, 2x/x= 10/2

x = 5

5. 5x + 20 = 50

or, 5x = 50-20

or, 5x = 30

or, 5x/x = 30/5

x = 6

Hope this helps...

Good luck on your assignment...

Answer:

  Always true

Step-by-step explanation:

If you can't express the number as a ratio of integers, multiplying or dividing it by integers will not make it so you can.

If π is irrational, 2π is also irrational.

It is always true that the product of a rational and an irrational number is irrational.

Answer:

all ways true

Step-by-step explanation:

Answer:

a. ans=1

b. ans=2/5

c. ans=4

hope u understood...

Answer:

z = (X-Mean)/SD

X = Mean + (z*SD)

The z value which separates the bottom 75% (100%-25%) from the top 25% is + 0.6745

Therefore, Q3 = X = 107 + (0.6745*16) = 117.8

Step-by-step explanation:

Answer:

The answer is "As the number of files increases, the storage space used decreases."

Step-by-step explanation:

When the music files are put into storage they take up space, this causes the storage space to decrease.

Answer:

As the number of files increases, the storage space used increases.

Answer:

7x-1

Step-by-step explanation:

The solution is : If f(x) = 5x – 2 and g(x) = 2x + 1, then the value of  (f+g)(x) is : 7x-1.

Function, in mathematics, an expression, rule, or law that defines a relationship between one variable (the independent variable) and another variable.

here, we have,

given that,

If f(x) = 5x – 2 and g(x) = 2x + 1,

now, we have to find (f+g)(x).

so, we have,

f(x) = 5x – 2

and g(x) = 2x + 1

now,

(f+g)(x)

=f(x)+g(x)

=5x-2+(2x+1)

=5x-2+2x+1

=7x-1

Hence, The solution is : If f(x) = 5x – 2 and g(x) = 2x + 1, then the value of  (f+g)(x) is : 7x-1.

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