Example 13, can anyone tell me why the bases can be converted into x and y?

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

Determine the type of correlation that exists in the given data set. Age (years) 23 45 39 74 63 52 59 28 35 11 26 49 IQ 76 82 11

Lyrx [107]

Answer:

B -0.104

Step-by-step explanation:

Step 1: Write the formula for correlation

r = total xy

√Total x² x Total y²

Step 2: Make a table to calculate all values

Table is attached in the picture below

Step 3 : Solve

Mean of X = Total X/ Total number of X

= 507/12

= 106.33

Mean of Y = Total Y/ Total number of Y

= 1276/ 12

= 42.25

r = total xy

√Total x² x Total y²

r = -352.05/ √3656.25 x 3122.66698

r = -0.104

-0.104 is negative

This negative correlation means there is an inverse correlation between variables.

6 0

3 years ago

Read 2 more answers

Solve y=3x-4 and y=2/5x 9

mojhsa [17]

I need the sign between the (2/5)x and the 9

5 0

3 years ago

Find the point that is 3/4 of the distance P (-6,-5) to the point Q (2,7)

Zarrin [17]

Using proportions, the coordinates of the point 3/4 of the way from P to Q are: (0,4).

<h3>What is a proportion?</h3>

A proportion is a fraction of a total amount, and the measures are related using a rule of three. Due to this, relations between variables, either direct or inverse proportional, can be built to find the desired measures in the problem.

We want to find the coordinates of point M(x,y) 3/4 of the way from P to Q, hence the rule is given by:

M - P = 3/4(Q - P)

For the x-coordinate, we have that:

x + 6 = 3/4(2 + 6)

x + 6 = 6

x = 0.

For the y-coordinate, we have that:

y + 5 = 3/4(7 + 5)

y + 5 = 9.

y = 4.

The coordinates are (0,4).

More can be learned about proportions at brainly.com/question/24372153

#SPJ1

8 0

1 year ago

Help????? Pls?????????

Fantom [35]

18 men in the dance recital

6 0

3 years ago

Read 2 more answers

Example 13, can anyone tell me why the bases can be converted into x and y? ​

Example 13, can anyone tell me why the bases can be converted into x and y?