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3 years ago

Help me with this probability question for (7th grade math)

Mathematics

2 answers:

Agata [3.3K]3 years ago

6 0

Answer:

15 times

Step-by-step explanation:

Probability is calculated as

probability = $\frac{favourableoutcomes}{count}$

Here a favourable outcome is an even number : 2, 4, 6 and the count is 6

P(even number) = $\frac{3}{6}$ = $\frac{1}{2}$

expected even number = $\frac{1}{2}$ × 30 = 15 times

ElenaW [278]3 years ago

4 0

There is a 3/6 possibility for an even number to get chosen.

Might be wrong

bye

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Numbers with a sum of 1

riadik2000 [5.3K]

Answer:

0.5 + 0.5, 0 + 1, 0.6 + 0.4, etc etc

Step-by-step explanation:

4 0

2 years ago

Read 2 more answers

Please help me out with these slopes.

inysia [295]

Remember, the slope formula is y2-y1 over x2-x1. To plug numbers into the formula, find two points. Then, you substitute the points into the formula.

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3 years ago

A rocket is launch from atop a 74 foot cliff with an initial velocity of 113 ft/s the height of the rocket above the ground at t

EleoNora [17]

Answer: We will use the QUADRATIC FORMULA.

x=7.6659375

Step-by-step explanation:

Use the Quadratic formula

a=-16,b=113,c=74

And then use the quadratic formula and you get x=7.6659375

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3 years ago

The rates of on-time flights for commercial jets are continuously tracked by the U.S. Department of Transportation. Recently, So

tatyana61 [14]

Answer:

The probability that at least 13 flights arrive late is 2.5196 $\times 10^{-6}$ .

Step-by-step explanation:

We are given that Southwest Air had the best rate with 80 % of its flights arriving on time.

A test is conducted by randomly selecting 18 Southwest flights and observing whether they arrive on time.

The above situation can be represented through binomial distribution;

$P(X = x) = \binom{n}{r}\times p^{r} \times (1-p)^{n-r} ; x = 0,1,2,3,.........$

where, n = number of trials (samples) taken = 18 Southwest flights

r = number of success = at least 13 flights arrive late

p = probability of success which in our question is probability that

flights arrive late, i.e. p = 1 - 0.80 = 20%

Let X = <u><em>Number of flights that arrive late</em></u>.

So, X ~ Binom(n = 18, p = 0.20)

Now, the probability that at least 13 flights arrive late is given by = P(X $\geq$ 13)

P(X $\geq$ 13) = P(X = 13) + P(X = 14) + P(X = 15) + P(X = 16) + P(X = 17) + P(X = 18)

= $\binom{18}{13}\times 0.20^{13} \times (1-0.20)^{18-13}+ \binom{18}{14}\times 0.20^{14} \times (1-0.20)^{18-14}+ \binom{18}{15}\times 0.20^{15} \times (1-0.20)^{18-15}+ \binom{18}{16}\times 0.20^{16} \times (1-0.20)^{18-16}+ \binom{18}{17}\times 0.20^{17} \times (1-0.20)^{18-17}+ \binom{18}{18}\times 0.20^{18} \times (1-0.20)^{18-18}$

= $\binom{18}{13}\times 0.20^{13} \times 0.80^{5}+ \binom{18}{14}\times 0.20^{14} \times 0.80^{4}+ \binom{18}{15}\times 0.20^{15} \times 0.80^{3}+ \binom{18}{16}\times 0.20^{16} \times 0.80^{2}+ \binom{18}{17}\times 0.20^{17} \times 0.80^{1}+ \binom{18}{18}\times 0.20^{18} \times 0.80^{0}$

= 2.5196 $\times 10^{-6}$ .

7 0

3 years ago

9. What is the coefficient of y^2? in the expansion of (x + y)^2??

klemol [59]

Answer:

The coefficient of y² will be 1, which we can see when we expand the expression:

(x + y)²

= (x +y)(x + y)

= x² + xy + xy + y²

= x² + 2xy + y²

3 0

3 years ago

Help me with this probability question for (7th grade math)​

Help me with this probability question for (7th grade math)