2) An $80 text book was on sale for $49.60 at the used book store. By what percent did the book decrease in price?​

Answer:

81 squared feet

Step-by-step explanation:

Answer:

The answer is 2  1/2

Step-by-step explanation:

First you turn 3 3/4 into an improper fraction .To do that you multiply the denominator x the whole number + the numerator = 4x3=12 +3=15/4.

Then you turn 1 1/2 into an improper fraction .To do that you multiply the denominator x the whole number + the numerator =2x1+1=3/2

15/4 divided by 3/2 but get your answer you have to reverse 3/2 into 2/3 and you multiply instead of dividing .

15/4 x 2/3 =15 x2 = 30 , 4x3=12  so your answer will be 30/12 but it can be simplified because they are both multiple of 6 . So , 30 divided by 6 = 5 and 12 divided by 6 = 2 so then you answer is 5/2 but it is an improper fraction so you divide 5 by 2 and you get 2 and a remainder of 1/2=2 1/2

Answer:

9880

Step-by-step explanation:

[tex]C^3_{40}=\frac{40!}{3!(40-3)!} =\frac{40!}{3!*37!}=13*19*40=9880.[/tex]

Answer:

16,928

Step-by-step explanation:

just solve it in calculation so you can see the answer

and remember study hard to go to bts concert joke to your dream

Answer:

3a^4

Step-by-step explanation:

Simplify the expression.

Answer:

Confidence interval variance [21.297 ; 64.493]

Confidence interval standard deviation;

4.615, 8.031

Step-by-step explanation:

Given :

Variance, s² = 34.34

Standard deviation, s = 5.86

Sample size, n = 27

Degree of freedom, df = 27 - 1 = 26

Using the relation for the confidence interval :

[s²(n - 1) / X²α/2, n-1] ; [s²(n - 1) / X²1-α/2, n-1]

From the chi distribition table :

X²α/2, n-1 = 41.923 ; X²1-α/2, n-1 = 13.844

Hence,

[34.34*26 / 41.923] ; [34.34*26 / 13.844]

[21.297 ; 64.493]

The 95% confidence interval for the population variance is :

21.297 < σ² < 64.493

Standard deviation is the square root of variance, hence,

The 95% confidence interval for the population standard deviation is :

4.615 < σ < 8.031

The population variance of 95% confidence interval is [tex]4.615<\sigma<8.031[/tex] and this can be determined by using the given data.

Given :

First, determine the degree of freedom.

[tex]df = 27-1=26[/tex]

The determine the confidence interval using the below formula:

[tex]\left(\dfrac{s^2(n-1)}{X^2_{\alpha/2,(n-1) }}\right);\left(\dfrac{s^2(n-1)}{X^2_{(1-\alpha)/2,(n-1) }}\right)[/tex]

Now, using the chi distribution the above expression becomes:

[tex]\left(\dfrac{34.34\times 26}{41.923 }}\right);\left(\dfrac{34.34\times 26}{13.844 }}\right)[/tex]

Simplify the above expression.

(21.297 ) ; (64.493)

So, the population variance of 95% confidence interval is:

[tex]\begin{aligned}\\21.297&<\sigma^2<64.493\\4.615&<\sigma<8.031\\\end{alingned}[/tex]

For more information, refer to the link given below:

https://brainly.com/question/7635845

Answer:

The 95% confidence interval for the population mean gas price in Gainesville is between $2.54 and $2.62.

Step-by-step explanation:

We have the standard deviation of the sample, so we use the t-distribution to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 28 - 1 = 27

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 27 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 2.0.52

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.052\frac{0.09}{\sqrt{27}} = 0.04[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is $2.58 - $0.04 = $2.54

The upper end of the interval is the sample mean added to M. So it is $2.58 + $0.04 = $2.62.

The 95% confidence interval for the population mean gas price in Gainesville is between $2.54 and $2.62.

Answer:

0.45 cents

Step-by-step explanation:

I think

Answer:

Ans: 9 ÷ 100 × 4 = 0.09 × 4 = 0.036$

9514 1404 393

Answer:

  24

Step-by-step explanation:

The angles of a linear pair are supplementary.

  (6x +3)° +33° = 180°

  6x = 144 . . . . . . . . . . . divide by °, subtract 36

  x = 24 . . . . . . . . divide by 6

Answer:

42

Step-by-step explanation:

Answer:

Step-by-step explanation:

-2              2

3(2)           -3(2)

Answer:

d. 0.0047

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

When the distribution is normal, we use the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes 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.

Population:

We have that [tex]\mu = 7.7, \sigma = 0.2[/tex]

Sample of 3:

[tex]n = 3, s = \frac{0.2}{\sqrt{3}} = 0.1155[/tex]

Which of the following represents the probability that the mean weight of a random sample of 3 olives from this population is greater than 8 grams?

This is 1 subtracted by the pvalue of Z when X = 8. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

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

[tex]Z = \frac{8 - 7.7}{0.1155}[/tex]

[tex]Z = 2.6[/tex]

[tex]Z = 2.6[/tex] has a pvalue of 0.9953

1 - 0.9953 = 0.0047

The probability is given by option d.

You can calculate the z score for the specified sample and then use the z tables to find the p value(probability) needed.

The probability that the mean weight of a random sample of 3 olives from this population is greater than 8 grams is given by

Option d : 0.0047

Suppose that the sample is of size 'n', then we have the z score(we are converting random variable X to standard random variable Z) as:

[tex]Z = \dfrac{X - \overline{x}}{s} = \dfrac{X - \mu}{\sigma/\sqrt{n}}[/tex]

where [tex]\overline{x}[/tex] is mean of the sample

s is the standard deviation of the sample,

and we used the central limit theorem which says that a sample from a normally distributed population with [tex]mean = \mu[/tex] and standard deviation = [tex]\sigma[/tex] can have its mean approximated by population mean and its standard deviation approximated by [tex]s = \dfrac{\sigma}{\sqrt{n}}[/tex]

Let the weight of the the olives for the given crop of olives of a particular company for taken random sample is given by X (a random variable)

Then, we have:

[tex]X \sim N(7.7, 0.2)[/tex]

where

[tex]\mu = 7.7, \sigma = 0.2[/tex]

Thus, we have:

[tex]\overline{x} = \mu, s = \sigma/\sqrt{n} = 0.2/\sqrt{3}[/tex]

Using the given facts, we get the needed probability as:

[tex]P( X> 8)[/tex] sample size n  = 3)

Then, using the z score, we get):

[tex]P(X > 8) = 1 - P(X \leq 8) = 1 - P(Z \leq \dfrac{8 - 7.7}{0.2/\sqrt{3}})\\\\P(X > 8)=1- P(Z \leq \dfrac{0.3\sqrt{3}}{0.2}) = 1- P(Z \leq 1.5 \times \sqrt{3} )\\\\P(X > 8) = 1 - P(Z \leq 2.59) = 1- 0.9952 \approx 0.0047[/tex]

Thus,

The probability that the mean weight of a random sample of 3 olives from this population is greater than 8 grams is given by

Option d : 0.0047

Learn more about standard normal distribution here:

https://brainly.com/question/14989264

Answer:

Step-by-step explanation:

Given

Solve for x

Answer:

2

Step-by-step explanation:

first answer deleted by moderator... even when it was correct... i did more explaining on that one, but they kindly deleted my answer and didn't even show my full answer after they had deleted it like some other moderators do which i always appreciate.

Answer:

69.12 ft

Step-by-step explanation:

The formula for circumference of a circle is 2πr

= 2 × 3.142× 11

= 69.12

Hence the circumference of the circle is 69.12 ft

Answer:

probably C I'm terrible at math but that look about right

Answer:5y-25

Step-by-step explanation:

Answer:

5y - 25

Step-by-step explanation:

that expression shown 25 less than 5y

hope this helps...

Answer:

8/15 and 3/10

Answer:

x = 12

Step-by-step explanation:

Answer:

Step-by-step explanation:

when x=5, 4(5)-3y=18

                        3y=2

                          y=2/3

The coordinate would be(5,2/3)

Answer:

The width of the rectangle = 1.15 inches

Step-by-step explanation:

Explanation:-

Given that the length of the rectangle = [tex]\frac{1}{2} inch[/tex]

The area of the rectangle = [tex]\frac{2.3}{4}[/tex] inch²

We have to find the width of the rectangle

The area of the rectangle = length × width

                                  [tex]\frac{2.3}{4} = \frac{1}{2} X width[/tex]

                    ⇒     2 × 2.3 = 4× width

                   ⇒      4.6 = 4 w

                  ⇒      w = 1.15 inches

Final answer:-

The width of the rectangle = 1.15 inches

Answer:

The simplified expression is 6k+19 .

Step-by-step explanation:

Answer:

1.375

Step-by-step explanation:

Answer: 11/2

Step-by-step explanation:

Answer is 0:72

hope it is helpful

Answer:

18/25

Step-by-step explanation:

Answer:

2x=  1 /2 y+ 2

Step-by-step explanation:

Solve for x.

2x−y=4

Add y to both sides.

2x−y+y=4+y

2x=y+4

Divide both sides by 2.

2x /2  =  y+4 /2

x= 1/ 2 y+2

The required point that is the solution to the equation 2x - y = 4 is at (2, -4)

In order to get the solution to the equation, we will need to get its x and y-intercept.

x- intercept is the point where y is zero.

Given the equation 2x - y = 4

If y = 0

2x - 0 = 4

2x = 4

x = 4/2

x = 2

Get the y-intercept

y intercept is the point where x = 0

if x = 0

2(0) - y = 4

-y = 4

y = -4

Hence the y-intercept is -4

The required point that is the solution to the equation is at (2, -4)

Learn more here: https://brainly.com/question/24609929

Answer:

(-1, -2)

Explanation:

Answer:I say 8 for $12.40

Step-by-step explanation:

Answer:

8 for 12.50

Step-by-step explanation:

12.50/8 = 1.55

3.00/2= 1.50

youre getting 6 more pens for only 5 cents more

Answer:

The slope of line perpendicular to line q is 8/3.

Step-by-step explanation:

Given that:

Slope of a line q is -3/8

Slope is the steepness of any line.

Let,

x be the slope of line perpendicular to line q.

The product of slopes of two perpendicular lines is equal to -1.

[tex]\frac{-3}{8}x = -1[/tex]

Multiplying both sides -8/3

[tex]\frac{-8}{3}*\frac{-3}{8}x=-1*\frac{-8}{3}[/tex]

x = 8/3

Hence,

The slope of line perpendicular to line q is 8/3.