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3 years ago

Which following statements are false

1 answer:

3 0

A) Vertical angles are congruent: It is true. Vertical angles are called opposite angles, so they are congruent. B) Angles with measures between 0- 90 degrees are complementary: It is false. Complementary angles are angles that the sum of their value is 90° C) Straight angles are complementary: it is false. Straight angles are angles which value is 180°. D) Angles with measure between 90 and 180 degrees are obtuse. This statement is true by definition <span>
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A number is chosen at random from 1 to 50. Find the probability of not selecting a multiple of 2.

r-ruslan [8.4K]

Lets look at the number of numbers between 1 and 50 which is not a multiple of 2. Its 1, 3, 5 ........... 47, 49.

That is 25 numbers.

So the required probability is 25/50 = 1/2 Answer

4 0

4 years ago

What is 34107.12cm to the nearest half centimeters? please explain

jok3333 [9.3K]

Answer:

17053.56

Step-by-step explanation:

Half a centimeter is 5 millimeters.

Brainliest??? PLS???

6 0

3 years ago

In a class of 18 students, 5 are math majors. A group of four students is chosen at random. (Round your answers to four decimal

ss7ja [257]

Answer:

(a) 0.2721

(b) 0.7279

Step-by-step explanation:

(a) If we choose only one student, the probability of being a math major is $\frac{5}{18}$ (because there are 5 math majors in a class of 18 students). So, the probability of not being a math major is $\frac{18}{18} - \frac{5}{18} = \frac{13}{18}$ (we subtract the math majors of the total of students).

But there are 4 students in the group and we need them all to be not math majors. The probability for each one of not being a math major is $\frac{13}{18}$ and we have to multiply them because it happens all at the same time.

P (no math majors in the group) = $\frac{13}{18} *\frac{13}{18}*\frac{13}{18}*\frac{13}{18} = (\frac{13}{18}) ^4$ = 0.2721

(b) If the group has at least one math major, it has one, two, three or four. That's the complement (exactly the opposite) of having no math majors in the group. That means 1 = P (at least one math major) + P (no math major). We calculated this last probability in (a).

So, P (at least one math major) = 1 - P(no math major) = 1 - 0.2721 = 0.7279

(c) In the group of 4, we need exactly 2 math majors and 2 not math majors. As we saw in (a), the probability of having a math major in the group is 5/18 and having a not math major is $\frac{13}{18}$ . We need two of both, that's $\frac{5}{18}*\frac{5}{18}*\frac{13}{18}*\frac{13}{18}$ . But we also need to multiply this by the combinations of getting 2 of 4, that is given by the binomial coefficient $\binom{4}{2}$ .

So, P (exactly 2 math majors) = $\binom{4}{2}*(\frac{5}{18} )^2*(\frac{13}{18})^2$ = $\frac{4!}{2!2!}*\frac{25}{324}*\frac{169}{324}$ = 0.2415

7 0

4 years ago

I need help with circumference

maw [93]

This is actually an area problem:
The diameter of the circle is 6 which is the width of the sandbox and the radius is 1/2 of the diameter so r=3
Formula for area= π(r^2) or pi*radius squareThe area of the circle would be 9π which is 28.27
Then you subtract it from the area of the sandbox which is 6*10=60
60-28.27=31.73 which rounds to 32 square feet
Answer: C
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6 0

3 years ago

In a manufacturing process, a machine produces bolts that have an average length of 3 inches with a variance of .03. If we rando

mars1129 [50]

Answer: 0.8413

Step-by-step explanation:

population mean = 3

population variance = 0.03

sd (standard deviation) = √0.03

Let x = sample mean

x has a mean of 3 and sd of √0.03/√3 = √0.01 = 0.1

And we can aprox the sample mean distribution using a normal distribution

Note: this approximation maybe is not so good (n = 3)

with mean = 3 and sd = 0.1

z = (x-3)/0.1 has a standard normal distribution

P(x<3.1) = P(z<(3.1-3)/0.1) = P(z<1) =0.8413

8 0

4 years ago