Please help.

assume that when adults with smartphones are randomly selected 15 use them in meetings or classes if 15 adult smartphones are ra

Tanzania [10]

Answer:

The probability that at least 4 of them use their smartphones is 0.1773.

Step-by-step explanation:

We are given that when adults with smartphones are randomly selected 15% use them in meetings or classes.

Also, 15 adult smartphones are randomly selected.

Let X = Number of adults who use their smartphones

The above situation can be represented through the binomial distribution;

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

where, n = number of trials (samples) taken = 15 adult smartphones

r = number of success = at least 4

p = probability of success which in our question is the % of adults

who use them in meetings or classes, i.e. 15%.

So, X ~ Binom(n = 15, p = 0.15)

Now, the probability that at least 4 of them use their smartphones is given by = P(X $\geq$ 4)

P(X $\geq$ 4) = 1 - P(X = 0) - P(X = 1) - P(X = 2) - P(X = 3)

= $1- \binom{15}{0}\times 0.15^{0} \times (1-0.15)^{15-0}-\binom{15}{1}\times 0.15^{1} \times (1-0.15)^{15-1}-\binom{15}{2}\times 0.15^{2} \times (1-0.15)^{15-2}-\binom{15}{3}\times 0.15^{3} \times (1-0.15)^{15-3}$

= $1- (1\times 1\times 0.85^{15})-(15\times 0.15^{1} \times 0.85^{14})-(105 \times 0.15^{2} \times 0.85^{13})-(455 \times 0.15^{3} \times 0.85^{12})$

= 0.1773

3 0

3 years ago

Will Mark Brainliest!!! Which statement represents the simplified form of the given equation and correctly describes the solutio

Iteru [2.4K]

The statement $14 \neq 15$ no solutions represents the simplified form of the given equation 6x + 14 = 3(2x + 5). Hence Option A is correct

Solution:

Given, equation is 6x + 14 = 3(2x + 5).

We have to find the correct options that represents the simplified form of the given equation and correctly describes the solution.

So, now let us simplify the given equation

⇒6x + 14 = 3(2x + 5) ⇒ 6x + 14 = 6x + 15 ⇒ 6x – 6x + 14 = 15 ⇒ 14 ≠ 15

As L.H.S not equals with R.H.S, no value of x can satisfy the equation and there will be no solution for given equation.

Hence, option A is correct.

4 0

3 years ago

Stacey and Michele both babysit in the evening.staceys hours rate is $10 for one child plus $2per additional child Michael hourl

lara31 [8.8K]

They have two children...
8 + 3c = 10 + 2c
c = 2

7 0

3 years ago

Read 2 more answers

Is (-1,5) a solution to each system? y=2x+7

Nadya [2.5K]

Answer:

Step-by-step explanation:

Plug (-1,5) into the equation y = 2x+7

5 = 2(-1)+7

5 = -2+7

5 = 5

The equation holds true, so (-1,5) is a solution to y = 2x+7

4 0

3 years ago

Read 2 more answers

PLEASE SOMEONE HELP ME

Soloha48 [4]

9514 1404 393

Answer:

a) 5 cm

b) 8 cm

c) 9 m

Step-by-step explanation:

It can be worthwhile to work the last attachment (a) first, since these are all variations of the same triangle.

The Pythagorean theorem tells you the sum of the squares of the legs is the square of the hypotenuse.

Problem 6a:

3² +4² = x² . . . . fill in the given numbers; all measures in cm

9 + 16 = x² . . . . simplify exponents

25 = x² . . . . . . . simplify sum

x = √25 = 5 . . . take the square root.

x = 5 cm . . . . . . apply units

__

Note that this triangle is a 3-4-5 right triangle. That is a set of side lengths (ratios) that is useful to remember. In this problem set, you see it again immediately.

__

Problem 6b:

Shortest-to-longest, the side ratios of the given triangle are ...

6 : x : 10

For some x', this is ...

3 : x' : 5 . . . . . . . . . . . . . matches a 3-4-5 triangle with x' = 4

The scale factor is 6/3 = 10/5 = 2, so we have ...

x = 2·x' = 2·4 = 8

x = 8 cm . . . . . with units

__

Problem 6c:

The side ratios are ...

x : 12 : 15 which reduces to x' : 4 : 5

This matches a 3-4-5 triangle with x' = 3, and a scale factor of 12/4 = 15/5 = 3.

Then ...

x = 3·x' = 3·3 = 9

x = 9 m . . . . . with units

8 0

3 years ago