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2 years ago

Please answer correctly !!!!!!!!!!!! Will mark Brianliest !!!!!!!!!!!!!!!!!!

Mathematics

1 answer:

OleMash [197]2 years ago

8 0

Answer:

For every 5 students scoring in the 60s, there were 2 students scoring in the 70s.

Step-by-step explanation:

There are 40 scorers in the 60s and 16 scorers in the 70s. These are ratios, so the ratio between the 60s and the 70s would be 40/16. This fraction can be simplified down to 5/2. This means that for every 5 students scoring in the 60s, 2 scored in the 70s.

You might be interested in

Is the number there three? if you answer to me i will give you twenty Points.

juin [17]

Answer:

Step-by-step explanation:

3 x 2 = 6

1 x 2 = 2

hope it helps

sorry if I'm wrong

7 0

2 years ago

If a student randomly guesses at 20 multiple-choice questions, find the probability that the student gets exactly four correct.

ad-work [718]

Answer:

Probability = 0.190

Step-by-step explanation:

Given:

Number of questions, 'n' = 20

Each question has four choices.

Let event of choosing correct answer be success and its probability be represented by 'p'.

Therefore, event of choosing wrong answer is failure and its probability be represented by 'q'.

Now, probability of success is choosing one correct answer out of 4 options. So, $p=\frac{1}{4}=0.25$

Now, 'p' and 'q' are complements of each other. Therefore,

$q=1-p=1-0.25=0.75$

Now, we need 4 successes. Therefore, $x=4$

Using Bernoulli's theorem to find 'x' successes from 'n' questions, we get:

$P(x)=_{x}^{n}\textrm{C}p^xq^{n-x}$

Plug in 4 for 'x', 20 for 'n', 0.25 for 'p' and 0.75 for 'q'. Solve.

$P(4)=_{4}^{20}\textrm{C}(0.25)^4(0.75)^{20-4}\\P(4)=_{4}^{20}\textrm{C}(0.25)^4(0.75)^{16}\\P(4)=4845\times (0.25)^4\times (0.65)^{16}\\\\P(4)=0.1896\approx0.190$

Therefore, the probability of getting 4 correct answers out of 20 questions is 0.190.

6 0

3 years ago

The mean of the data set is 15.What number is missing? 9,12,16,18,23

maxonik [38]

The number 12 is missing in the data set.

<u>Step-by-step explanation</u>:

The numbers are 9,12,16,18,23.
The missing number is assumed to be 'x'

Mean = Sum of the integers / Total number of integers.

15 = (9+12+16+18+23+x) / 6

15 = (78+x) / 6

90 = 78+x

x = 90-78

x = 12

3 0

3 years ago

Determine where V(z)=z4(2z−8)3 is increasing and decreasing.

Marat540 [252]

Answer and Explanation:

A function is said to be increasing, if the derivative of function is f’(x) > 0 on each point. A function is said to be decreasing if f”(x) < 0.

Let y = v (z) be differentiable on the interval (a, b). If two points z1 and z2 belongs to the interval (a, b) such that z1 < z2, then v (z1) ≤ v (z2), the function is increasing in this interval.

Similarly, the function y = v(z) is said to be decreasing, when it is differentiable on the interval (a , b).

Two points z1 and z2 Є (a, b) such that z1 > z2, then v (z1) ≥ v(z2). The function is decreasing on this interval.

The function y = v (z)

The derivative of function Y’ = v’(z) is positive, then the function is increasing.

The function y = v (z)

The derivative of function y’ is negative, then the function is decreasing.

8 0

3 years ago

A human heart beats an average of 80 beats per minute. How many beats is this in an hour?

Aleksandr [31]

Answer:

4800 beats an hour

Step-by-step explanation:

there are 60 minutes in and hour

the heart beats 80 times per minute( that is actually a very high heart rate)

80*60=4800 per hour

8 0

3 years ago

Read 2 more answers