32.45 is most precise . Precise means how many points after decimal is reached. Accurate means how close your measurement of a value is that to the true value. Eg :Say 35cm is the measure of length of a body and a person got the measurement to be 34 . Another person2 got the measurement to be 32.88 . So in this case the first person has an accurate answer as he is close to the true value 35 , but person2 is more precise as he has two decimal places.

6 0

3 years ago

Solve the inequality. Graph the solution.<br> 7z< -28

Zepler [3.9K]

Answer: The answer is -9

Step-by-step explanation:

7z<-28= -9

Because we take the -28 and add 19 because that's the common denominator and we come up with -9

6 0

2 years ago

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.

Lower endpoint: 0.422cc/m³

Upper endpoint: 0.452 cc/m³

4 0

3 years ago