If a/b=7/2, then 2a= ______
A) 7b
B) 4b
C) 2b
D) 14b

Answer:

a) The sample mean is 1260 and the standard deviation is 48.

b) The 90% confidence interval for the mean of all tree-ring dates from this archaeological site is (1230, 1290).

Step-by-step explanation:

Question a:

Mean is the sum of all values divided by the number of values. So

[tex]\overline{x} = \frac{1285 + 1187 + 1222 + 1194 + 1268 + 1316 + 1275 + 1317 + 1275}{9} = 1260[/tex]

Standard deviation is the square root of the sum of the differences squared between each value and the mean, divided by the one less than the sample size. So

[tex]s = \sqrt{\frac{(1285-1260)^2 + (1187-1260)^2 + (1222-1260)^2 + (1194-1260)^2 + (1268-1260)^2 + ...}{8}} = 48[/tex]

The sample mean is 1260 and the standard deviation is 48.

Question b:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

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

df = 9 - 1 = 8

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 8 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 1.8595

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 1.8595\frac{48}{\sqrt{9}} = 30[/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 1260 - 30 = 1230

The upper end of the interval is the sample mean added to M. So it is 1260 + 30 = 1290

The 90% confidence interval for the mean of all tree-ring dates from this archaeological site is (1230, 1290).

Answer:

3x^2+5x+1

Step-by-step explanation:

(x^2 + 3x + 1) + (2x^2 + 2x)

Combine like terms

x^2 + 2x^2  + 3x +2x   +1

3x^2+5x+1

Answer:

[tex]3x^{2} + 5x + 1[/tex]

Step-by-step explanation:

Step 1:  Combine like terms

[tex](x^{2} + 3x + 1) + (2x^{2} + 2x)[/tex]

[tex](x^{2} + 2x^{2} + (3x + 2x) + (1)[/tex]

[tex]3x^{2} + 5x + 1[/tex]

Answer:  [tex]3x^{2} + 5x + 1[/tex]

Answer:

12

Step-by-step explanation:

(18+3)=21

(9-5)=4

4x21=84

84/2=42

42-30=12

Answer:

12

Step-by-step explanation:

((18+3)x(9-5))/2-30

=((21)x(4))/2-30

=(84)/2-30

=42-30

=12

Answer:

2x+1

Step-by-step explanation:

The expression = (5x+3)-(3x+2) = 2x+1

It's divergent because 1/√(5 - x) is defined only for x < 5, which means the integral from 5 to infinity doesn't exist.

Answer:

r + s - 19

General Formulas and Concepts:

Algebra I

Step-by-step explanation:

Step 1: Define

Identify

r - 7 + s - 12

Step 2: Simplify

Answer:

Consider the angle Ф.

the line opposite to Ф is the perpendicular -> PQ = 5cm

The base is the line with whom the perpendicular has 90° angle -> PR = 12cm

Finally, hypotenuse is the line opposite to the 90° which is QR= 13cm

Answer:

hypotenuse = QR = 13 cm

Perpendicular = PQ = 5 cm

Base = PR = 12 cm

Answer:

Sixteen million, one hundred and seven thousand, three hundred twenty

Step-by-step explanation:

Answer:

23,000,550

Step-by-step explanation:

A million has six zeroes, so twenty three million is

23,000,000

Since five hundred fifty is not in the thousands, it replaces the last trio of zeroes.

We have the number in standard form as

23,000,550

Answer:

23000550

Step-by-step explanation:

9514 1404 393

Answer:

  b) 24 miles per gallon

Step-by-step explanation:

The usual metric measure of vehicle fuel efficiency is liters per 100 km. Greater efficiency is indicated by a lower value.

In the US, the measure is usually miles per gallon. Greater efficiency is indicated by a higher value. Since we want the efficiency expressed in miles per gallon, we need to divide distance by fuel consumption.

  (distance)/(fuel used) = (100 km)/(10 L)

  = (100 km)/(10 L) × (1 mi)/(1.6 km) × (3.8 L)/(1 gal) = (100×3.8)/(10×1.6) mi/gal

  = 23.75 mi/gal ≈ 24 mi/gal

Answer:

1/7 is the probabiltiy

Step-by-step explanation:

Answer:

Step-by-step explanation:

Take the beginning number and add or subtract each transaction to get a new balance. For example,

                  349.45

-     23.42 = 326.03

-     14.95  = 311.08

+   276.50 = 587.58

-    219.93 =  367.65

-       76.84 = 290.81

Answer:iiii

Step-by-step explanation:iiiii

Answer:

17.9

Step-by-step explanation:

Answer:

Prove that all sides are congruent and that the slopes of consecutive sides are opposite reciprocals. Step-by-step explanation: In order to two segmets to be perpendicular, the slope of both lines must be opposite and reciprocals, having a 90° interception and forming a square.

Answer:

Step-by-step explanation:

The next term is going to be simply 38*19 = 722

The series is geometric which means that you multiply from one term to get to the next.

The ratio of 19, and the current term is 38. So to get to the next term, multiply 38 * 19

Answer:

the next one is .857 I hope this helps you :)

Answer:

12.56 cents

14.08 cent

Step-by-step explanation:

The unit price for each of the following items could be obtained thus :

The unit price = price of one item

Therefore, given that x numbers of a certain item cost y ;

The unit price will be : y / x

frozen orange juice

16.0 oz at $2.01

12 oz at $1.69

If 16 oz cost $2.01

1 oz = $2.01 / 16 = $0.125625 * 100 = 12.56 cents

If 12 oz = $1.69

1 oz = $1.69 / 12 = $0.1408333 * 100 = 14.08 cent

Answer:

0.3 is the right answer.

Step-by-step explanation:

hope this helps

9514 1404 393

Answer:

Step-by-step explanation:

Dilation has no effect on angle measures, so ∠A = ∠A'.

Point A is the center of dilation, so doesn't move. Any line through point A will still go through point A after dilation. Lines AD and A'D' are not distinct.

Answer:

x = -16/7​

Step-by-step explanation:

7x+25=9​

Subtract 25 from each side

7x+25-25=9-25

7x = -16

Divide each side by 7

7x/7 = -16/7

x = -16/7​

Answer:

[tex]7x + 25 = 9 \\ 7x = 9 - 25 \\ 7x = - 16 \\ x = \frac{ - 16}{7} \\ x = - 2.29[/tex]

Step-by-step explanation:

I hope it helped U

stay safe stay happy

Answer:

5/33

Step-by-step explanation:

The probability of selecting a white marble is 4/12 = 1/3(because we have 4 white marbles and 12 marbles in total )

The probability of selecting a blue marble is 5/11 (because we have 5 blue marbles and 11 marbles left(1 has been drawn already) )

Probability of selecting a white and then blue marble equals 1/3*5/11 = 5/33

Solution :

Defining the following events as :

B : Being a Business major

α : Studying at the library

∴ Given that :

[tex]$P(B) = \frac{45}{100}$[/tex]

         = 0.45

Again, P [ Studying at the library | Being a Business major ] = 2 P [ Studying at the library | Being a non business major ]

[tex]$P[ \alpha | B] = 2 P[\alpha | B^C]$[/tex]   .......(1)

Again,

[tex]$P[\text{Studying at the library } | \text{ Being a business major}] = \frac{1}{2} = 0.50$[/tex]

[tex]$P(\alpha | B) = 0.50$[/tex]

From (1), we get

[tex]$P(\alpha | B^C) = \frac{1}{2} . P(\alpha | B)$[/tex]

              [tex]$=\frac{1}{2} \times 0.50$[/tex]

              = 0.25

Therefore, we need,

= P[  The students is a Business major | The student studies at the library ]

[tex]$=P(B | \alpha)$[/tex]

By Bayes theorem

[tex]$=\frac{P(B). P(\alpha | B)}{P(B).P(\alpha | B) + P(B^C). P(\alpha | B^C)}$[/tex]

[tex]$=\frac{0.45 \times 0.50}{0.45 \times 0.50 + 0.55 \times 0.25}$[/tex]

= 0.6207

9514 1404 393

Answer:

  A

Step-by-step explanation:

To form the conjugate, change the sign between terms. Leave the radical alone.

  the conjugate is √(x-5) +2 . . . . matches choice A

[tex]\huge\bold\pink{ANSWER} [/tex]

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

A

[tex] \sqrt{ \times - 5 + 2} [/tex]

tsurezure children

#BrainliestBunch

Answer:

Should be (C). Can't verify.

545

ED2021

Answer:

The relation is linear

Step-by-step explanation:

Answer:

Yes, the relationship shown is linear. The equation of the line is y=-1.25x-13.25.

Step-by-step explanation:

This data is linear as y decreases at a constant rate. The equation of a line is y=mx+b, where m=slope and b=y intercept

To find m:

m=[tex]\frac{y2-y1}{x2-x1}[/tex]

m=[tex]\frac{(-2)-(-7)}{(-9)-(-5)}[/tex]

m=[tex]\frac{5}{-4}[/tex]

m=[tex]-\frac{5}{4}[/tex]=-1.25

To find b, you can use any of the given points:

(-9,-2)

(-2)=-1.25(-9)+b

-2=11.25+b

-2-11.25=b

b=-13.25

Therefore, using the calculated values for m and b:

y=mx+b

y=-1.25x-13.25

because it's value will always be same

Answer:

This value doesn't depend on x or y

It'll be the same things always

Answer:

64

------

125

Step-by-step explanation:

(4/5)^3

We can rewrite this as

4^3

----------

5^3

64

------

125

Answer:

384 cubic inches

Step-by-step explanation:

first find the volume of the fish tank by multipying the length, width, and height.

v=lwh

 =(16in)(4in)(12in)

 = 768 cubic inches (This answer is equal to the volume of the entire fish tank, however we need to find how much water half the tank can hold. To figure this out, we need to divide 768 by 2. And you should get 384 cubic inches)

Answer:

384

Step-by-step explanation:

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