The points , 2r and , 104 lie on a line with slope 54 .

A chemist examines 12 sedimentary samples for bromide concentraction. The mean bromide concentration for the sample date is 0.43

Umnica [9.8K]

Answer:

a) $z = 1.645$

b) Lower endpoint: 0.422cc/m³

Upper endpoint: 0.452 cc/m³

Step-by-step explanation:

Population is approximately normal, so we can find the normal confidence interval.

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.9}{2} = 0.05$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.05 = 0.95$ , so $z = 1.645$ . This is the critical value, the answer for a).

Now, find M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

$M = 1.645*\frac{0.0325}{\sqrt{12}} = 0.015$

The lower end of the interval is the sample mean subtracted by M. So it is 0.437 - 0.015 = 0.422cc/m³.

The upper end of the interval is the sample mean added to M. So it is 0.437 + 0.015 = 0.452 cc/m³.

b)

Lower endpoint: 0.422cc/m³

Upper endpoint: 0.452 cc/m³

4 0

3 years ago

At a football game, 12 people are wearing red jerseys and 15 people are wearing white jerseys. Write the ratio of red to white j

Anastasy [175]

Answer:

12:15 (simplified: 4:5)

12/15 (simplified: 4/5)

12 to 15 (simplified: 4 to 5)

Hope this helped!

6 0

2 years ago

Read 2 more answers

Can u show me how to solve this problem 0.11 times 0.91

lisov135 [29]

Answer:

0.1001

Step-by-step explanation: Your answer is 0.1001

0.91

0.11

1011

0990

00000

0.1001

Hope this helps you!!! :)

3 0

3 years ago

Find the missing parts of the triangle. Round to the nearest tenth when necessary or to the nearest minute as appropriate.

Katena32 [7]

Answer:

A) A = 27.3°, B = 56.1°, C = 96.6°

Step-by-step explanation:

Use the Law of Cosines:

A = arccos [(b² + c² - a²)/(2bc)] = arccos [(13.2² + 15.8² - 7.3²)/(2*13.2*15.8)] = 27.3°
B = arccos [(a² + c² - b²)/(2ac)] = arccos [(7.3² + 15.8² - 13.2²)/(2*7.3*15.8)] = 56.1°
C = 180° - (A + B) = 180° - (27.3° + 56.1°) = 96.6°

Correct choice is A.

3 0

3 years ago

B=3/a+2 make a the subject

katen-ka-za [31]

Answer:

Solve for a

A= 3/B - 2

Step-by-step explanation:

5 0

2 years ago