Many ancient tombs were cut from limestone rock that contained uranium. Since most such tombs are not​ well-ventilated, they may contain radon gas. In one​ study, the radon levels in a sample of 12 tombs in a particular region were measured in becquerels per cubic meter (Bq/m3). For this​ data, assume that x(over-bar)= 3,469 Bq/m3 and s= 1,135 Bq/m3. Use this information to​ estimate, with 95% confidence, the mean level of radon exposure in tombs in the region. Interpret the resulting interval.

Answer: 9

Step-by-step explanation:

Answer: [tex]=(29.1596\text{ degrees},\ 30.2404\text{ degrees})[/tex]

Step-by-step explanation:

Given: Sample size: n = 41

Sample mean [tex]\overline{x}= 29.7[/tex] degrees

Population standard deviation [tex]\sigma=2.7[/tex] degrees

Confidence level (c) =  80% =0.80

Significance level (a) = 1- c = 1-0.80 = 0.20

z-score for 80% confidence level : z = 1.2816   [from z-table]

Confidence level for population mean :-

[tex]\overline{x}\pm z\dfrac{\sigma}{\sqrt{n}}[/tex]

[tex]=29.7\pm ( 1.2816)\dfrac{2.7}{\sqrt{41}}[/tex]

[tex]=29.7\pm ( 1.2816)\dfrac{2.7}{6.403124}[/tex]

[tex]=29.7\pm ( 1.2816)(0.42167)[/tex]

[tex]=29.7\pm 0.5404[/tex]

[tex]=(29.7-0.5404,\ 29.7+0.5404)[/tex]

[tex]=(29.1596,\ 30.2404)[/tex]

Hence, 80% confidence interval for the temperatures in the freezer [tex]=(29.1596\text{ degrees},\ 30.2404\text{ degrees})[/tex]

Answer:

1. no solution

2. one solution

3. infinitely many solutions

Step-by-step explanation:

1. 4= -3

false

2. -5=6c+7

2=6c

c=3

3. 5a+7=5a+7

true

Answer:

No solution

One solution

Infinite number of solutions

Step-by-step explanation:

Answer:

B

Step-by-step explanation:

Answer:

$586.04 is your answer

Answer:

P [ X > 23,22 ]  = 0,8798      or  P [ X > 23,22 ]  =  87,98 %

Step-by-step explanation:

P [ X > 23,22 ]  =  1  -  P [X ≤ 23,22 ]

P [X ≤ 23,22 ] =  ( X - μ₀ ) / σ /√n

P [X ≤ 23,22 ] = ( 23,22 - 36,25 )/ 6,50/√36

P [X ≤ 23,22 ] =  - 13,03 *6 / 6,50

P [X ≤ 23,22 ] = - 12,02        or       P [X ≤ 23,22 ] = 12,02 %

(note the - sign only mean that values on the left tail of the bell shape curve)

Then

P [ X > 23,22 ]  =  1  -  0,1202

P [ X > 23,22 ]  = 0,8798      or  P [ X > 23,22 ]  =  87,98 %

Answer:

a) True

b) True

C) false

Step-by-step explanation:

just a guess..... Merry Christmas

The anwser is -415

hope this helped!

Answer:

Both take time together = 36 / 5 hours = 7.2 hours

Step-by-step explanation:

Given:

Briana take time = 12 hour

Henry take time = 18 hour

Find:

Both take time together

Computation:

Briana 1 hour work = 1/12

Henry 1 hour work = 1/18

Both take time together = 1/[1/12+1/18]

Both take time together = 1/[5/36]

Both take time together = 36 / 5 hours = 7.2 hours

Answer:

The slope of the first graph is [tex]\frac{2}{3}[/tex] and the slope of the second graph is [tex]\frac{4}{2} = 2[/tex]

Step-by-step explanation:

First Graph

1. use rise over run to find the slope

2. the line goes up 2 numbers before it touches again

3. the line goes ever 3 numbers before it touches again

Second Graph

1. use rise over run to find the slope

2. the line goes up 4 numbers before touching again

3. the line goes over 2 numbers before touching again

Answer:

8+4t

Step-by-step explanation:

combine 3t and t then do 6t - 4t getting 8+4t

Answer:

I think

Step-by-step explanation:

-5,-2,-1,0,3 that is definitely my answer

Answer:

the last one

Step-by-step explanation:

......

...

Answer:

30= 20 so, that’s 10 dollars of

                                            1o+ 7. 5=17. 5+10=27 .50

Step-by-step explanation:

I took the test hope this helps

Answer:

9/10 bc it would be .90 in decimals

Step-by-step explanation:

Answer:

9/10 is

Step-by-step explanation:

9/10 as a decimal is 0.9 and if you line them up, 0.9 is greater than 0.45

Answer:

We should attempt synthetic division to find when

x

3

−

k

x

2

+

2

k

x

−

15

x

−

3

has a remainder of

0

, which would signify that it is a factor of the polynomial.

The synthetic substitution would be set up as:

3

−

∣

∣

∣

1

−

k

2

k

−

15

−−−

−−−

−−−

−−−

−−−

|

0

Treating the synthetic division like any other synthetic division problem, we see that

3

−

∣

∣

∣

1

−

k

2

k

−

15

−−−

−−−

3

−−−−−−−−

−

3

k

+

9

−−−−−−−−

−

3

k

+

27

−−−−−−−−−

1

−

k

+

3

−

k

+

9

|

0

If the remainder equals

0

, then we know that

−

3

k

+

27

+

(

−

15

)

=

0

Solve this to see that

k

=

4

.

Thus,

(

x

−

3

)

is a factor of

x

3

−

4

x

2

+

8

x

−

15

.

Answer:

30°  is one of the degree measures of the angles.

Hence, option (A) is true.

Step-by-step explanation:

Given that the degree measure of one of two complementary angles is twice that of the other.

Complementary angles

Thus the equation becomes

x + 2x = 90°

3x =  90°

Divide both equations by 3

3x/3 = 90°/3

x = 30°

Therefore, 30°  is one of the degree measures of the angles.

Hence, option (A) is true.

The degree measure of one of two complementary angles is twice that of the other. What is one of the degree measures of the angles?

A.) 30 degrees

Let one angle = x

According to statement,

Another angle = 2 × first angle

[tex] \sf : \implies Another \: angle = 2x[/tex]

Now, we know that sum of complementary angles is 90°

Hence,

[tex] \sf : \implies x + 2x = 90^{\circ}[/tex]

[tex] \sf : \implies 3x = 90^{\circ}[/tex]

[tex] \sf : \implies x = \dfrac{\cancel{90}^{\circ}}{\cancel{3}}[/tex]

[tex] \sf : \implies x = 30^{\circ}[/tex]

[tex] \Large \underline{\boxed{\sf{ x = 30^{\circ} }}}[/tex]

Therefore, one of the angle is 30°.

Another angle = 2 × 30° = 60°

Francisco is probably a beaner or mongrel with no business working or even existing in a white nation.

Answer:

5.5 feet per second or 330 feet per minute

Step-by-step explanation:

550/100 seconds = 5.5 feet per second  

5.5 x 60 = 330 feet per minute

Answer:

3.75 mph (miles per hour)

(i finally got the right answer, ignore my comment, i am so sorry it was wrong T_T)

Answer:

1 hour and 15 minuets

Step-by-step explanation:

5 hours and he was hedging for 25% of that time.

25%=.25

5(0.25)

1.25

A quarter of an hour is 15 minutes.

So the final answer would be 1 hour and 15 minuets.

Answer:

I also think b one is correct

Answer:

Answer:

3

Step-by-step explanation:

Answer:

It's 3 square units.

Count the "squares" and you get 3 and it's not real units so It's called "Square units".

:)

Answer:

no figures

Step-by-step explanation:

to work with and the answer is can't be determined

Step-by-step explanation:

Step 3 is incorrect, it should be x - 4 + x = x(x - 3).

x - 4 + x = x(x - 3)

2x - 4 = x² - 3x

x² - 5x + 4 = 0

(x - 4)(x - 1) = 0

x = 4 or x = 1.

x = 4 is rejected as 1 / (x - 4) will become 1 / 0 which is undefined.

=> x = 1.

Answer:

1. 8 x 8 ÷ 2

2. 64 ÷ 2 = 32

Step-by-step explanation:

(7+1) becomes 8 and 8 x 8 becomes 64

64 ÷ 2 = 32

Step-by-step explanation:

True

and the more mass the object had the greater gravitational force it is

P. S my opinion

Answer:4:24 I believe

Step-by-step explanation:

Answer:

4:25

Step-by-step explanation:

The little string stand for hour and the big string stands for the minutes

Answer:

Part B:

5) She will have $4445.244256 in 3 years

Part C:

1) She will have $8081.130039 in 10 years

2) He will have $13360.55059 in 8 years

Step-by-step explanation:

The formula of the compound interest is A = P [tex](1+\frac{r}{n})^{nt}[/tex], where

Part B:

5)

∵ P = $4250

∵ r = 1.5% = 1.5 ÷ 100 = 0.015

∵ n = 4 ⇒ Compounded quartly

∵ t = 3 years

→ Substitute them in the formula above

∴ A = 4250 [tex](1+\frac{0.015}{4})^{4(3)}[/tex]

∴ A = 4250 [tex](1.00375)^{12}[/tex]

∴ A = 4445.244256

∴ She will have $4445.244256 in 3 years

Part C:

1)

∵ Grace deposits $6000

∴ P = 6000

∵ The account is compounded semi-annually at 3%

∴ r = 3% = 3 ÷ 100 = 0.03

∴ n = 2 ⇒ compounded semi-annually

∵ The time is 10 years

∴ t = 10

→ Substitute them in the formula above

∴ A = 6000 [tex](1+\frac{0.03}{2})^{2(10)}[/tex]

∴ A = 6000 [tex](1.015)^{20}[/tex]

∴ A = 8081.130039

∴ She will have $8081.130039 in 10 years

2)

∵ Danial opens an account that is compounded semi-annually at 5%

∴ r = 5% = 5 ÷ 100 = 0.05

∴ n = 2 ⇒ compounded semi-annually

∵ He deposits $9000

∴ P = 9000

∵ The time is 8 years

∴ t = 8

→ Substitute them in the formula above

∴ A = 9000 [tex](1+\frac{0.05}{2})^{2(8)}[/tex]

∴ A = 9000 [tex](1.025)^{16}[/tex]

∴ A = 13360.55059

∴ He will have $13360.55059 in 8 years