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2 years ago

Please help please please please

Mathematics

1 answer:

slamgirl [31]2 years ago

8 0

If two events are dependent on each other you have to multiply the probability of the first event times the probability of the second event.
first count all the marbles here there are 21
you are asked about picking two green marbles there are 7 out of the 21 total.
The first event would be 7/21
The second event would be 6/20 (since you didn't replace and you took out a green one)
now multiply your two fractions together:
and you get 1/10.

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Is 1|3 and 3|3 are equal ?

netineya [11]

No, they aren't. 3/3+ 1 whole

3 0

2 years ago

Read 2 more answers

If triangle ABC is isosceles and triangle DBE is equilateral what is the measure of angle C

luda_lava [24]

Answer:

43°

Step-by-step explanation:

For triangle ABC:

A = C so all we need to do is to calculate the value of B

The measure of angle ABD is given as 17° so the measure of angle EBC must be 17° as well

Since DBE is an equilateral triangle angle is DBE = 60°

17 + 17 + 60 = 94 this is the measure of angle B

The sum of interior angles in a triangle is equal to 180

A + B + C = 180

A + C + 94 = 180

A + C = 86 since A = C we divide 86 by 2

C = 43°

6 0

2 years ago

A 9-year-old girl did a science fair experiment in which she tested professional touch therapists to see if they could sense he

Orlov [11]

Answer:

We conclude that the the touch therapists does not use a method equivalent to random guesses.

Yes, the results suggest that touch therapists are effective.

Step-by-step explanation:

We are given that in a 9-year-old girl did a science fair experiment in which she tested professional touch therapists to see if they could sense her energy field.

Among 264264 trials, the touch therapists were correct 105105 times.

Let p = proportion that touch therapists uses a random guess method.

Here, random guess means; p = 50%

So, Null Hypothesis, $H_0$ : p = 50% {means that the touch therapists use a method equivalent to random guesses}

Alternate Hypothesis, $H_A$ : p $\neq$ 50% {means that the touch therapists does not use a method equivalent to random guesses}

The test statistics that would be used here One-sample z proportion statistics;

T.S. = $\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }$ ~ N(0,1)

where, $\hat p$ = sample proportion of touch therapists were correct = $\frac{105}{264}$ = 0.39

n = sample of trials = 264

So, test statistics = $\frac{\frac{105}{264} -0.50}{\sqrt{\frac{\frac{105}{264}(1-\frac{105}{264})}{264} } }$

= -3.395

The value of z test statistics is -3.395.

Now, at 0.05 significance level the z table gives critical value of -1.96 and 1.96 for two-tailed test. Since our test statistics does not lie within the range of critical values of z, so we have sufficient evidence to reject our null hypothesis as it will in the rejection region due to which we reject our null hypothesis.

Therefore, we conclude that the the touch therapists does not use a method equivalent to random guesses.

Yes, the results suggest that touch therapists are effective.

3 0

2 years ago

In the circle below, DB = 22 cm, and m<DBC = 60°. Find BC. Ignore my handwriting.

Karo-lina-s [1.5K]

Answer:

$BC=11\ cm$