Time spent using e-mail per session is normally distributed with a mean = to 8 minutes and standard deviation = 2minutes. If a random samples of 36 sessions were selected, the computed sample standard deviation would be

a. 0.25
b. 0.3333
c. 0.42
d. 0.48

Answers

Answer 1

Answer:

The correct option is (b) 0.3333.

Step-by-step explanation:

The standard deviation of the sampling distribution of sample mean [tex](\bar x)[/tex] is known as the standard error [tex](\sigma_{\bar x})[/tex].

The standard error is given as follows:

[tex]\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}[/tex]

The information provided is:

[tex]\mu=8\\\\\sigma=2\\\\n=36[/tex]

Compute the standard deviation of the sample mean as follows:

[tex]\sigma_{\bar x}=\frac{\sigma}{\sqrt{n}}[/tex]

    [tex]=\frac{2}{\sqrt{36}}\\\\=\frac{2}{6}\\\\=\frac{1}{3}\\\\=0.3333[/tex]

Thus, the standard deviation of the sample mean is 0.3333.


Related Questions

A signal light is green for 4 minutes, yellow for 10 seconds, and red for 3 minutes. If you drive up to this light, what is the probability that it will be green when you reach the intersection? Round your answer to two decimal places.

Answers

Answer:

0.56 is the required probability.

Step-by-step explanation:

Time for which signal shows green light = 4 minutes

Time for which signal shows yellow light = 10 seconds

Time for which signal shows red light = 3 minutes

To find:

Probability that the signal will show green light when you reach the destination = ?

Solution:

First of all, let us convert each time to same unit before doing any calculations.

Time for which signal shows green light = 4 minutes = 4 [tex]\times[/tex] 60 seconds = 240 seconds

Time for which signal shows yellow light = 10 seconds

Time for which signal shows red light = 3 minutes = 3 [tex]\times[/tex] 60 seconds = 180 seconds

Now, let us have a look at the formula for probability of an event E:

[tex]P(E) = \dfrac{\text{Number of favorable cases}}{\text {Total number of cases}}[/tex]

Here, E is the event that green light is shown by the signal.

Number of favorable cases mean the time for which green light is shown and Total number of cases is the total time (Time for which green light is shown + Time for which Yellow light is shown + Time for which red light is shown)

So, the required probability is:

[tex]P(E) = \dfrac{240}{240+10+180}\\\Rightarrow P(E) = \dfrac{240}{430}\\\Rightarrow \bold{P(E) \approx 0.56 }[/tex]

The area of the circle x² + y2 - 6x-4y +9 = 0 is​

Answers

Answer:

Your answer is here.Enjoy dude

Answer:

12.56 unit²

Step-by-step explanation:

Given:x² + y² - 6x - 4y + 9 = 0To find:The area of circleSolution:

The form of the circle is:

(x- h)² + (y-k)² = r²

Let's bring the given to the form of a circle as above:

x² + y² - 6x - 4y + 9 = 0x² - 6x  + y²-  4y + 9 = 0        ⇒ combining like terms and completing squarex² - 6x + 9 + y²- 4y + 4 = 4    ⇒ adding 4 to both sides(x-3)² + (y - 2)² = 2²                ⇒ got the form of this circle

As per the form, we got r² = 2², so the radius of circle is 2 units.

The area of circle:

A= πr² = 3.14×2² = 12.56 unit²

10/7p+13/8+15/2p=909/56 i NEED THiS solving multi step equations w fractions and #8 PLEASE

Answers

Answer:

P= 2

Step-by-step explanation:

10/7p+13/8+15/2p=-909/56

Combine like terms

10/7p+15/2p=-909/56-13/8

20p+105p/14=-909-13*7/56

125/14p=-909-91/56

125/14p= -1000/56

125/14p*14/125= -1000/56*14/125

simplify

P= 8/4=2

And for #8 n =1 I answered this question it

Search

The equation below is written in words. x plus ten equals two. What's the value of x?

Answers

Answer:

x+10 =2

x = -8

Step-by-step explanation:

plus means add

x+10 =2

Subtract 10 from each side

x+10-10 =2-10

x = -8

3.24 (4 being repeated) to a fraction

Answers

Answer:

  146/45

Step-by-step explanation:

Let x represent the value of the number of interest. Then we can do the following math to find its representation as a fraction.

  [tex]x=3.2\overline{4}\\10x=32.4\overline{4}\\10x-x=9x=32.4\overline{4}-3.2\overline{4}=29.2\\\\x=\dfrac{29.2}{9}=\boxed{\dfrac{146}{45}}[/tex]

__

Comment on procedure

The power of 10 that we multiply by (10x) is the number of repeated digits. Here, there is a 1-digit repeat, so we multiply by 10^1. If there were a 2-digit repeat, we would compute 10^2x -x = 99x to rationalize the number.

Give the domain and range of each relation using set notation​

Answers

Answer:

See below.

Step-by-step explanation:

First, recall the meanings of the domain and range.

The domain is the span of x-values covered by the graph.

And the range is the span of y-values covered by the graph.

1)

So, we have here an absolute value function.

As we can see, the domain of the function is all real numbers because the graph stretches left and right infinitely. Therefore, the domain of the function is:

[tex]\{x|x\in\textbb{R}\}[/tex]

(You are correct!)

For the range, notice how the function stops at y=7. The highest point of the function is (-2,7). There graph doesn't and won't ever reach above y=7. Therefore, the range of the graph is all values less than or equal to 7. In set notation, this is:

[tex]\{y|y\leq 7\}[/tex]

2)

We have here an ellipse.

First, for the domain. We can see the the span of x-values covered by the ellipse is from x=-4 to x=6. In other words, the domain is all values in between these two numbers and including them. Therefore, we can write it as such:

[tex]-4\leq x\leq 6[/tex]

So x is all numbers greater than or equal to -4 but less than or equal to 6. This describes the span of x-values. In set notation, this is:

[tex]\{x|-4\leq x\leq 6\}[/tex]

For the range, we can see that the span of x values covered by the ellipse is from y=-5 to y=1. Just like the domain, we can write it like this:

[tex]-5\leq y\leq 1[/tex]

This represents all the y-values between -5 and 1, including -5 and 1.

In set notation, thi is:

[tex]\{y|-5\leq y\leq 1\}[/tex]

Select the correct answer -1/4(12x+8) is less than it equal to -2x+11

Answers

Answer:

x ≤ [tex]\frac{9}{5}[/tex]

Step-by-step explanation:

Given

[tex]\frac{1}{4}[/tex](12x + 8) ≤ - 2x + 11 ← distribute parenthesis on left side

3x + 2 ≤ - 2x + 11 ( add 2x to both sides )

5x + 2 ≤ 11 ( subtract 2 from both sides )

5x ≤ 9 ( divide both sides by 5 )

x ≤ [tex]\frac{9}{5}[/tex]

Answer: x≤ 3/-10

Explanation: Firstly given that

-¼(12x+8) ≤ -2x+11

• Divide by 4

4X-¼(12x+8) ≤-2x+11

= -12x + 8 ≤ -2x + 11

• Group like terms

-12x + 2x ≤ 11 - 8

= -10x/10 ≤ 3/-10

x≤ 3/-10

The table shows the height, in meters, of an object that is dropped as time passes until the object hits the ground. A 2-row table with 10 columns. The first row is labeled time (seconds), x with entries 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.6. The second row is labeled height (meters), h with entries 100, 98.8, 95.1, 89.0, 80.4, 69.4, 55.9, 40.0, 21.6, 0. A line of best fit for the data is represented by h = –21.962x + 114.655. Which statement compares the line of best fit with the actual data given by the table? According to the line of best fit, the object would have hit the ground 0.6 seconds later than the actual time the object hit the ground. According to the line of best fit, the object was dropped from a lower height. The line of best fit correctly predicts that the object reaches a height of 40 meters after 3.5 seconds. The line of best fit predicts a height of 4 meters greater than the actual height for any time given in the table.

Answers

Answer: A. According to the line of best fit, the object would have hit the ground 0.6 seconds later than the actual time the object hit the ground.

The statement first "According to the line of best fit, the object would have hit the ground 0.6 seconds later than the actual time the object hit the ground" is correct.

What is the line of best fit?

A mathematical notion called the line of the best fit connects points spread throughout a graph. It's a type of linear regression that uses scatter data to figure out the best way to define the dots' relationship.

We have a line of best fit:

h = –21.962x + 114.655

As per the data given and line of best fit, we can say the object would have impacted the ground 0.6 seconds later than it did according to the line of best fit.

Thus, the statement first "According to the line of best fit, the object would have hit the ground 0.6 seconds later than the actual time the object hit the ground" is correct.

Learn more about the line of best fit here:

brainly.com/question/14279419

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An experimental probability is ______ likely to approach the theoretical probability if the number of trials simulated is larger. A. as B. more C. less D. not

Answers

Answer:

B. More

Step-by-step explanation:

This is according to the law of large numbers

An experimental probability is more likely to approach the theoretical probability if the number of trials simulated is larger.

What is an experimental probability and theoretical probability?

Experimental probability is an experimental outcome whereas theoretical probability is a possible or expected outcome.

An experimental probability is more likely to approach the theoretical probability if the number of trials increased because of the law of large numbers which states that the average of the results obtained from a large number of trials should be close to the expected value and tends to become closer to the expected value as more trials are performed

Thus using the concept of the law of large numbers we can say that an experimental probability is more likely to approach the theoretical probability.

Learn more about probability here:

https://brainly.com/question/9627169

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At the age of 10, Edgar received an inheritance of $10,000. His father wants to invest the money in an account that will double in value in 8 years. Approximately what interest rate does the father need to find in order to reach his goal?

Answers

Answer:

9%

Step-by-step explanation:

Use the rule of 72.  If you want the money to double in 8 years, it will need to be at 9 percent interest rate to reach this goal.

Brian needs to paint a logo using two right triangles. The dimensions of the logo are shown below. What is the difference between the area of the large triangle and the area of the small triangle? ​

Answers

Answer:

7.5 cm²

Step-by-step explanation:

Dimensions of the large ∆:

[tex] base (b) = 3cm, height (h) = 9cm [/tex]

[tex] Area = 0.5*b*h = 0.5*3*9 = 13.5 cm^2 [/tex]

Dimensions of the small ∆:

[tex] base (b) = 2cm, height (h) = 6cm [/tex]

[tex] Area = 0.5*b*h = 0.5*2*6 = 6 cm^2 [/tex]

Difference between the area of the large and the small ∆ = 13.5 - 6 = 7.5 cm²

A particle moves according to a law of motion s = f(t), t ≥ 0, where t is measured in seconds and s in feet. (If an answer does not exist, enter DNE.) f(t) = t3 − 8t2 + 27t

Answers

The question is not clear, but it is possible to obtain distance, s, from the given function. This, I would show.

Answer:

s = 17 units

Step-by-step explanation:

Given f(t) = t³ - 8t² + 27t

Differentiating f(t), we have

f'(t) = 3t² - 16 t + 27

At t = 0

f'(t) = 27

This is the required obtainaible distance, s.

On a coordinate plane, 2 lines are shown. Line A B has points (negative 4, negative 2) and (4, 4). Line C D has points (0, negative 3) and (4, 0). Which statement best explains the relationship between lines AB and CD? They are parallel because their slopes are equal. They are parallel because their slopes are negative reciprocals. They are not parallel because their slopes are not equal. They are not parallel because their slopes are negative reciprocals.

Answers

Answer:

A. they are parallel because their slopes are equal.

Step-by-step explanation:

edge 2020

Answer:

its A in egde

Step-by-step explanation:

Word phrase for algebraic expression 15-1.5/d

Answers

Answer: 1.5 less than 15 is divided by a number d.

Step-by-step explanation:

I need help will rate you branliest

Answers

Answer:

[tex] {x}^{2} + 5x + 10[/tex]

Answer:

[tex]\large \boxed{x^2 +5x+10}[/tex]

Step-by-step explanation:

A polynomial is an expression that has variables, coefficients, and constants.

An example of a polynomial can be x² - 6x + 2.

The probability density function for random variable W is given as follows: Let x be the 100pth percentile of W and y be the 100(1 – p)th percentile of W, where 0

Answers

Answer:

Step-by-step explanation:

A probability density function (pdf) is used for continuous random variables. That is why p is between 0 and 1 (the two extremes - 0 and 1 - exclusive).

X = 100pth percentile of W

Y = 100(1-p)th percentile of W

Expressing Y as a function of X;

Y = 100(1-p)th = 100th - 100pth

Recall that 100pth is same as X, so substitute;

Y = 100th - X

where 100th = hundredth percentile of W and X = 100pth percentile of W  

if f(x)=3x-3 and g(x)=-x2+4,then f(2)-g(-2)=

Answers

Answer:

3

Step-by-step explanation:

f(x)=3x-3

g(x)=-x^2+4,

f(2) = 3(2) -3 = 6-3 =3

g(-2) = -(-2)^2+4 = -4+4 = 0

f(2)-g(-2)= = 3-0 = 3

Explain how to perform a​ two-sample z-test for the difference between two population means using independent samples with known.

Answers

Answer:

The steps 1-7 have been explained

Step-by-step explanation:

The steps are;

1) We will verify that the population standard deviations are known and that the population is normally distributed which means the sample size must be a minimum of 30.

2) We will state the null and alternative hypothesis

3) We will determine the critical values from the relevant tables

4) From the critical values gotten, we will determine it's corresponding region where it can be rejected.

5)We will calculate the value of the test statistic from the formula;

z = [(x1' - x2') - (μ1 - μ2)]/√[((σ1)²/n1) + ((σ2)²/n2)]

6) If the value of the test statistic gotten from step 5 above falls in the region of rejection noted in step 4,then we will reject the null hypothesis

7) After rejection of the null hypothesis, we will now give a decision/conclusion on the claim.

What is the domain of f?

Answers

Answer:

-5 ≤x ≤6

Step-by-step explanation:

The domain is the values that x can take

X goes from -5 and includes -5 to x =6 and includes 6

-5 ≤x ≤6

Answer:

See attached!

Step-by-step explanation:

(05.06A LC)

Line segment AB has a length of 4 units. It is translated 1 unit to the right on a coordinate plane to obtain line segment A'B'. What is the length

of A'B'?

1 unit

4 units

5 units

6 units

Answers

Answer:

4 units

Step-by-step explanation:

A transformation is the movement of a point from one position to another position. If a shape is transformed all its points are also transformed. Types of transformations are translation, rotation, reflection and dilation.

If a shape is transformed, the length of its sides and shape remains the same, only the position changes.

If Line segment AB has a length of 4 units. It is translated 1 unit to the right on a coordinate plane to obtain line segment A'B, the length of A'B' remains the same which is 4 unit. To prove this:

Let A be at ([tex]x_1,y_1[/tex]) and B be at ([tex]x_2,y_2[/tex]). The length of AB is:

[tex]AB=\sqrt{(y_2-y_1)^2+(x_2-x_1)^2}[/tex]

If AB is translated to the right by 1 unit the new points are A' at ([tex]x_1+1,y_1[/tex]) and B' at ([tex]x_2+1,y_2[/tex]). The length of A'B' is:

[tex]A'B'=\sqrt{(y_2-y_1)^2+(x_2+1-(x_1+1))^2}=\sqrt{(y_2-y_1)^2+(x_2+1-x_1-1)^2}\\\\A'B'=\sqrt{(y_2-y_1)^2+(x_2-x_1)^2}[/tex]

AB = A'B' = 4 units

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

Answers

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

Find the reciprocal of the equation in standard form. The selected answer is incorrect.

Answers

Answer:

C

Step-by-step explanation:

reciprocal of z=1/z

[tex]z=2(cos \frac{\pi }{4} +i sin\frac{\pi }{4} )=2e ^{i \frac{\pi } {4}\\\frac{1}{z}=\frac{1}{2e^{i \frac{\pi}{4} } }\\\frac{1}{z} =\frac{1}{2} e^{-i\frac{\pi}{4} } \\\frac{1}{z} (cos\frac{\pi}{4} -isin\frac{\pi}{4} ) \\\frac{1}{z}=\frac{1}{2} (\frac{\sqrt{2} }{2} -\frac{\sqrt{2} }{2} )\\\frac{1}{z} =\frac{\sqrt{2} }{4} -i \frac{\sqrt{2 } }{4}[/tex]

Which expression is equivalent to (jk)l? A. (j + k) + l B. j(kl) C. (2jk)l D. (j + k)l

Answers

Answer:

B. j(kl)

Step-by-step explanation:

(jk)l

We can change the order we multiply and still get the same result

j(kl)

Answer:

Step-by-step explanation:

its B i did it

Find the sum of (5x3 + 3x2 - 5x + 4) and (8x3 -5x2 + 8x + 9)

Answers

Answer:

(5x³+3x²-5x+4) + (8x³-5x²+8x+9)

= 5x³+3x²-5x+4 +8x³-5x²+8x+9

= 5x³+8x³+3x²-5x²-5x+8x+4+9

= 13x³-2x²+3x+13

Hope this helps

if u have question let me know in comments ^_^

Write "six and thirty-four thousandths" as a decimal

Answers

Answer:

6.034

Step-by-step explanation:

6 is a whole number.

.034 because it is 34 thousandths, not 34 hundredths.

what is the distance between the first and third quartiles of a data set called?

Answers

Answer:

Interquartile range is the distance between the first and third of a data.

Step-by-step explanation:

Hope it will help you :)

A cabinet door has a perimeter of 76 inches. Its area is 357 square inches. What are the dimensions of the door?

Answers

Answer:

  17 by 21 inches

Step-by-step explanation:

The perimeter is twice the sum of the dimensions, and the area is their product, so you have ...

  L + W = 38

  LW = 357

__

Solution:

  W(38 -W) = 357 . . . . . substitute for L

  -(W^2 -76W) = 357 . . expand on the left

  -(W^2 -38 +19^2) = 357 -19^2 . . . . complete the square

  (W -19)^2 = 4 . . . . . . . write as a square

  W -19 = ±√4 = ±2 . . . take the square root; next, add 19

  W = 19 ±2 = {17, 21} . . . . if width is one of these, length is the other

The dimensions are 17 by 21 inches.

f as a function of x is equal to the square root of quantity 4 x plus 6, g as a function of x is equal to the square root of quantity 4 x minus 6 Find (f + g)(x). x times the square root of 8 4x square root of 8 times x The square root of quantity 4 times x plus 6 plus the square root of quantity 4 times x minus 6

Answers

Answer:

Last one

Step-by-step explanation:

The function f is:

● f (x)= √(4x+6)

The function g is:

● g(x) = √(4x-6)

Add them together:

● f+g (x)= √(4x+6 )+ √(4x-6)

Answer:

[tex]\large \boxed{{\sqrt{4x+6} + \sqrt{4x-6} }}[/tex]

Step-by-step explanation:

[tex]f(x)=\sqrt{4x+6}[/tex]

[tex]g(x)=\sqrt{4x-6}[/tex]

[tex](f+g)(x)[/tex]

[tex]f(x)+g(x)[/tex]

Add both functions.

[tex](\sqrt{4x+6} )+ (\sqrt{4x-6} )[/tex]

1
1 point
mZABD = 79
D
C
V
(5x + 4)
(8x - 3)
В B.
A
x= type your answer...
2
1 point

Answers

Answer:

x = 6

Step-by-step explanation:

∠ DBC + ∠ ABC = ∠ ABD , substitute values

5x - 4 + 8x - 3 = 79

13x + 1 = 79 ( subtract 1 from both sides )

13x = 78 ( divide both sides by 13 )

x = 6

Stock prices used to be quoted using eighths of a dollar. Find the total price of the transaction. 400 shares of national semi at 135 1/2

Answers

Answer:

The value is [tex]T = \$54200[/tex]

Step-by-step explanation:

From the question we are told that

      The  number of shares is  n  =  400

      The rate  of each share is  [tex]k = 135\frac{1}{2} = 135.5[/tex]

Generally the total price is mathematically represented as

     [tex]T = 400 * 135.5[/tex]

      [tex]T = \$54200[/tex]

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