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3 years ago

It would help me a lot if someone answered this :) Thanks in advance!

Mathematics

2 answers:

sukhopar [10]3 years ago

6 0

Answer: number of student age group 13-18 who likes rock are 186

See this table if you’d like

katovenus [111]3 years ago

4 0

Answer:

the total number who liked pop or rock music ik the age geoup is 186

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A pattern of letter arrangements begins with 3steps below. First, continue the pattern for 3 more step:

mart [117]

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3 years ago

What does the point (2, 120) represent on the graph?

Nonamiya [84]

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2 years ago

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Four interior angles of a pentagon measure 156 degrees 72 degrees 98 degrees and 87 degrees. What is the measure of the final in

zepelin [54]

Answer:

127°

Step-by-step explanation:

The sum of the interior angles of a polygon is

sum = 180°(n - 2) ← n is the number of sides

here n = 5 ( Pentagon), hence

sum = 180° × 3 = 540°

To find the fifth angle subtract the sum of the 4 given angles from 540

angle = 540° - (156 + 72 + 98 + 87) = 540° - 413° = 127°

6 0

3 years ago

When circuit boards used in the manufacture of compact disc players are tested, the long-run percentage of defectives is 5%. Let

sergiy2304 [10]

Answer:

(a) P(X=3) = 0.093

(b) P(X≤3) = 0.966

(c) P(X≥4) = 0.034

(d) P(1≤X≤3) = 0.688

(e) The probability that none of the 25 boards is defective is 0.277.

(f) The expected value and standard deviation of X is 1.25 and 1.089 respectively.

Step-by-step explanation:

We are given that when circuit boards used in the manufacture of compact disc players are tested, the long-run percentage of defectives is 5%.

Let X = the number of defective boards in a random sample of size, n = 25

So, X ∼ Bin(25,0.05)

The probability distribution for the binomial distribution is given by;

$P(X=r)= \binom{n}{r} \times p^{r}\times (1-p)^{n-r} ; x = 0,1,2,......$

where, n = number of trials (samples) taken = 25

r = number of success

p = probability of success which in our question is percentage

of defectivs, i.e. 5%

(a) P(X = 3) = $\binom{25}{3} \times 0.05^{3}\times (1-0.05)^{25-3}$

= $2300 \times 0.05^{3}\times 0.95^{22}$

= 0.093

(b) P(X $\leq$ 3) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)

= $\binom{25}{0} \times 0.05^{0}\times (1-0.05)^{25-0}+\binom{25}{1} \times 0.05^{1}\times (1-0.05)^{25-1}+\binom{25}{2} \times 0.05^{2}\times (1-0.05)^{25-2}+\binom{25}{3} \times 0.05^{3}\times (1-0.05)^{25-3}$

= $1 \times 1 \times 0.95^{25}+25 \times 0.05^{1}\times 0.95^{24}+300 \times 0.05^{2}\times 0.95^{23}+2300 \times 0.05^{3}\times 0.95^{22}$

= 0.966

(c) P(X $\geq$ 4) = 1 - P(X < 4) = 1 - P(X $\leq$ 3)

= 1 - 0.966

= 0.034

(d) P(1 ≤ X ≤ 3) = P(X = 1) + P(X = 2) + P(X = 3)

= $\binom{25}{1} \times 0.05^{1}\times (1-0.05)^{25-1}+\binom{25}{2} \times 0.05^{2}\times (1-0.05)^{25-2}+\binom{25}{3} \times 0.05^{3}\times (1-0.05)^{25-3}$