How do you solve x-6>7=

Suppose 88% of all batteries from a supplier have acceptable voltages. A certain type of flashlight requires two D batteries, an

ira [324]

Answer:

0.3036 = 30.36% probability that at least 9 of the flashlights function properly.

Step-by-step explanation:

For each flashlight, there are only two possible outcomes. Either it works, or it does not. Flashlights are independent. This means that we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

Flashlight works correctly if both its batteries have acceptable voltages:

Each battery has an 88% = 0.88 probability of working correctly(having acceptable voltage), so the probability of the flashlight working correctly is given by:

$p = (0.88)^2 = 0.7744$

10 flashlights.

This means that $n = 10$

What is the probability that at least 9 of the flashlights function properly?

This is

$P(X \geq 9) = P(X = 9) + P(X = 10)$

In which

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 9) = C_{10,9}(0.7744)^{9}.(0.2256)^{1} = 0.2260$

$P(X = 10) = C_{10,10}(0.7744)^{10}.(0.2256)^{0} = 0.0776$

$P(X \geq 9) = P(X = 9) + P(X = 10) = 0.2260 + 0.0776 = 0.3036$

0.3036 = 30.36% probability that at least 9 of the flashlights function properly.

6 0

3 years ago

MATH QUESTION DOWN BELOW

netineya [11]

Add x/2 to both sides. Result: 1/3 > 3/5 + x/2

Subtract 3/5 from both sides. Result: 1/3 - 3/5 > x/2

Mult. all terms by 30 to remove the fractions (30 is the LCD): 10 - 45 > x

Simplify: -35 > x, or x < -35.

I do not see why this does not match any of the possible solutions given. Do you?

5 0

3 years ago

Arthur can throw a ball twice as far as Beatrice. Beatrice can throw a ball one-third as far as Cory. Cory can throw a ball twic

sdas [7]

Answer:

A : D

4 : 3

Step-by-step explanation:

We'll use the first letter of their names as the heading for the ratio.

The first line states:

A : B

2 : 1

The second line states:

B : C

1/3 : 1

The third line states:

C : D

2 : 1

We have three different ratios but we know that they are related to one another so we are going to combine them by equating the common ratio of the different ratios.

Let's look at the ratio with a fraction first.

B : C

1/3 : 1

If we ×3 throughout, this can also be written as:

B : C

1 : 3

Now B in the first and second ratio is the same number and we are able to combine them. We can write them all together like this:

A : B : C

2 : 1 : 3

In the third ratio, C is 2, however in the ratio we have now C is 3. We can make them the same number by ×3 throughout the third ratio and ×2 throughout the ratio we have now.

C : D

2 : 1

6 : 3

A : B : C

2 : 1 : 3

4 : 2 : 6

We can see that our ratio for C is the same number and we can now combine the ratios.

A : B : C : D

4 : 2 : 6 : 3

The question asked for A : D so we can take just the values of A and D.

A : D

4 : 3

I hope this helps :)

3 0

3 years ago

Indica si el número es primo o compuesto?

Flura [38]

todos los numeros primos son: 2,3,5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89 y 97.

y los otros numeros que no mencione son conpuestos.

3 0

3 years ago

The cylinder has a height of 30cm and radius 11cm. work out the total surface area of cylinder

ozzi

Answer:

total surface area=2832.66 cm^2

Step-by-step explanation:

11^2(3.14)x2=area of ends=760.26 cm^2

11x2x3.14=circumference=69.08 cm

69.08x30=area of side=2072.4 cm^2

2072.4+760.26=2832.66 cm^2

8 0

3 years ago