HELP PLS

Look at the triangle ABC. What length of side AB of the triangle? a.2 b.square root of 20 c.6 d.square root of 38

Y_Kistochka [10]

I think is b cuz I know foe a fact;)

4 0

2 years ago

To reduce laboratory costs, water samples from five public swimming pools are combined for one test for the presence of bacteri

aleksklad [387]

Answer:

Step-by-step explanation:

Given that:

The numbers of the possible public swimming pools are 5

From past results, we have 0.007 probability of finding bacteria in a public swimming area.

In the public swimming pool, the probability of not finding bacteria = 1 - 0.007

= 0.993

Thus;

Probability of combined = Probability that at least one public

sample with bacteria swimming area have bacteria

Probability of combined sample with bacteria = 1 - P(none out of 5 has

bacteria)

Probability of combined sample with bacteria = 1 - (0.993)⁵

= 1 - 0.9655

= 0.0345

Thus, the probability that the combined sample from five public swimming areas will show the presence of bacteria is 0.0345

From above, the probability that the combined sample shows the presence of bacteria is 0.0345 which is lesser than 0.05.

Thus, we can conclude that; Yes, the probability is low enough that there is a need for further testing.

6 0

3 years ago

Need help with this geometry work show work hard for me pls answer fast due now

kati45 [8]

Answer:

3) answer is 120 4) 105

Step-by-step explanation

3) 180 - (70+50) = 60

180-60 = 120 <-- thats the answer

4) 180 - ( 80+25) = 75

180 - 75 = 105 < thats the answer

4 0

2 years ago

The Weschler Intelligence Scale for Children (WISC) is an intelligence test designed for children between the ages of 6 and 16.

Ostrovityanka [42]

Answer:

a) $\bar X = 121.4$

b) $SE = \frac{\sigma}{\sqrt{n}}= \frac{15}{\sqrt{40}}=2.372$

c) $121.4-1.64\frac{15}{\sqrt{40}}=117.51$

$121.4+1.64\frac{15}{\sqrt{40}}=125.29$

Step-by-step explanation:

Data given: 126,111,141,96,123,115,116,113,127,114,122,116,104,126,126,132,139,111,143,121,119,107,154,125,120,135,142,132,94,103,143,115,132,107,118,105,101,135,94,153

Part a

For this case we can calculate the sample mean with the following formula:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

And after replace we got:

$\bar X = 121.4$

Part b

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

For this case we assume that the population deviation is $\sigma=15$ , we can calculate the standard error with this formula:

$SE = \frac{\sigma}{\sqrt{n}}= \frac{15}{\sqrt{40}}=2.372$

Part c

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since the Confidence is 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a tabel to find the critical value. The excel command would be: "=-NORM.INV(0.05,0,1)".And we see that $z_{\alpha/2}=1.64$

Now we have everything in order to replace into formula (1):

$121.4-1.64\frac{15}{\sqrt{40}}=117.51$

$121.4+1.64\frac{15}{\sqrt{40}}=125.29$

8 0

3 years ago

Read 2 more answers

On which intervals is the function increasing? Choose<br> all that apply.

Alja [10]

The function is increasing on the intervals:

(-∞, 3] and [5, ∞)

Then the correct options are a and c.

<h3>On which intervals is the function increasing?</h3>

The function is increasing when, reading from left to right, we can see that the curve goes upwards.

By looking at the graph, we can see that the function increases between -∞ and 3, and also increases between 5 and ∞, then the correct options are a and c-

(-∞, 3] and [5, ∞)

If you want to learn more about increasing functions:

brainly.com/question/1503051

#SPJ1

8 0

1 year ago