Which situation can be represented by the expression -2-5−2−5minus, 2, minus, 5?

What percent of 19 is 11

Viktor [21]

The answer is 2.09 I hope this helped you

5 0

3 years ago

PLEASE HELP I BEG YOU

dangina [55]

If you're finding slope, the answer is 5/3

6 0

3 years ago

Read 2 more answers

A research scientist wants to know how many times per hour a certain strand of bacteria reproduces. The mean is found to be 9.8

svetlana [45]

Answer:

The 99% confidence interval for the true mean number of reproductions per hour for the bacteria is between 9.6 and 10.

Step-by-step explanation:

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

$\alpha = \frac{1-0.99}{2} = 0.005$

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 $1-0.005 = 0.995$ , so $z = 2.575$

Now, find the margin of error 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.

$M = 2.575\frac{2.4}{\sqrt{955}} = 0.2$

The lower end of the interval is the sample mean subtracted by M. So it is 9.8 - 0.2 = 9.6 reproductions per hour.

The upper end of the interval is the sample mean added to M. So it is 9.8 + 0.2 = 10 reproductions per hour.

The 99% confidence interval for the true mean number of reproductions per hour for the bacteria is between 9.6 and 10.

8 0

3 years ago

Solve for x. x/2≥−4<br> plz i need help!

Leto [7]

Answer:

x= -8

Step-by-step explanation:

x/2 is greater than of equal to -4

hence

x/2=-4

x=-4*2= -8

7 0

3 years ago

Working alone at its constant rate, pump X pumped out ¼ of the water in a tank in 2 hours. Then pumps Y and Z started working an

madam [21]

Answer:

The correct option is B) 12.

Step-by-step explanation:

Consider the provided information.

Working alone at its constant rate, pump X pumped out ¼ of the water in a tank in 2 hours.

As we know: $rate =\dfrac{ work}{time}$ ,

The rate of pump X is $\frac{\frac{1}{4}}{2} = \frac{1}{8}$

$\frac{1}{4}$ of the water is pumped out of the tank, that means only $\frac{3}{4}$ is left to be pumped out.

All 3 pumps pumped out the remaining $\frac{3}{4}$ of the water out in 3 hours.

The combined rate of all three pumps is: $\frac{\frac{3}{4}}{3} = \frac{1}{4}$

Pump Y, working alone at its constant rate, would have taken 18 hours to pump out the rest of the water.

The rate of pump Y = $\frac{\frac{3}{4}}{18} = \frac{1}{24}$

Let z is the time taken by pump Z, then the rate of pump Z is $\frac{1}{z}$ .

Therefore,

$\dfrac{1}{8}+\dfrac{1}{24}+\dfrac{1}{z}=\dfrac{1}{4}$

Multiplying both sides by 24 z.

$3z + z + 24 = 6z\\24 = 2z\\12 = z$

Hence, the correct option is B) 12.

5 0

3 years ago