Can someone help me pleaseeeeee

Help please 10 points

xxTIMURxx [149]

Answer:

Step-by-step explanation:

tell me the question ?? did not say the question ok ??

8 0

3 years ago

20 points Return to questionItem 4Item 4 20 points Police records in the town of Saratoga show that 13 percent of the drivers st

Sladkaya [172]

Answer:

a) 0.1423

b) 0.2977

c) 0.56

Step-by-step explanation:

For each driver stopped for speeding, there are only two possible outcomes. Either they have invalid licenses, or they do not. The probability of a driver having an invalid license is independent from other drivers. So we use the binomial probability distribution to solve this problem.

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.

In this problem we have that:

13 percent of the drivers stopped for speeding have invalid licenses.

This means that $p = 0.13$

14 drivers are stopped

This means that $n = 14$

(a) None will have an invalid license.

This is $P(X = 0)$

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

$P(X = 0) = C_{14,0}.(0.13)^{0}.(0.87)^{14} = 0.1423$

(b) Exactly one will have an invalid license.

This is $P(X = 1)$

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

$P(X = 1) = C_{14,1}.(0.13)^{1}.(0.87)^{13} = 0.2977$

(c) At least 2 will have invalid licenses.

Either less than 2 have invalid licenses, or at least 2 does. The sum of the probabilities of these events is decimal 1. Mathematically, this is

$P(X < 2) + P(X \geq 2) = 1$

We want $P(X \geq 2)$

So

$P(X \geq 2) = 1 - P(X < 2)$

In which

$P(X < 2) = P(X = 0) + P(X = 1) = 0.1423 + 0.2977 = 0.44$

$P(X \geq 2) = 1 - P(X < 2) = 1 - 0.44 = 0.56$

8 0

3 years ago

How many solutions does this system have?

8_murik_8 [283]

Answer:

1

Step-by-step explanation:

There can be 0, 1 or infinitely many solutions. 0 if they are parallel and are different lines, 1 if the slopes are different, and infinitely many if they are the same line.

2x - 4y = 8

x + y = 7

Change to y = mx + b

y = (1/2)x - 2

y = -x + 7

The slopes are different so there is 1 solution.

Hope this helps Please mark as brainliest and have a blessed day

6 0

3 years ago

Read 2 more answers

Ben, Tim, and Sam have to do a certain job. Ben can finish the job in 5 hours. Tim can finish the job in 6 hours. Sam can finish

Brut [27]

x is 7.5 hours

Step-by-step explanation:

Ben, Tim, and Sam have to do a certain job

Ben can finish the job in 5 hours
Tim can finish the job in 6 hours
Sam can finish the job in x hours
The three of them can finish the job in 2 hours if they work together

We need to find x

∵ Ben can finish the job in 5 hours

∴ The rate of Ben = $\frac{1}{5}$

∵ Tim can finish the job in 6 hours

∴ The rate of Tim = $\frac{1}{6}$

∵ Sam can finish the job in x hours

∴ The rate of Sam = $\frac{1}{x}$

They will working together to finish the job in two hours, that means the sum of their rate is equal to 1/2

∵ They can finish the job in 2 hours if they work together

∴ $\frac{1}{5}+\frac{1}{6}+\frac{1}{x}=\frac{1}{2}$

To add the fractions find the LCM for all denominators to make all fractions with same denominators

∵ The LCM of 5, 6 ans x is (5 × 6 × x) = 30 x,

- Divide it by each denominator to find the new numerators

∵ 30 x ÷ 5 = 6 x , 30 x ÷ 6 = 5 x , 30 x ÷ x = 30

- Change all the denominators to 30 x and then write the new

numerators of each fraction

∴ $\frac{6x}{30x}+\frac{5x}{30x}+\frac{30}{30x}=\frac{1}{2}$

Add the numerators and put the sum over 30 x

∵ $\frac{11x+30}{30x}=\frac{1}{2}$

- By using cross multiplication

∴ 2(11 x + 30) = 1(30 x)

- Simplify the both sides

∴ 22 x + 60 = 30 x

- Subtract 22 x from both sides

∴ 60 = 8 x

- Divide both sides by 8

∴ 7.5 = x

∴ The value of x is 7.5 hours

x is 7.5 hours

Learn more:

You can learn more about the word problems in brainly.com/question/10712420

#LearnwithBrainly

5 0

3 years ago

A coffee company wants to make sure that their coffee is being served at the right temperature. If it is too hot, the customers

Cerrena [4.2K]

Answer:

Null hypothesis: $\mu = 65$

Alternative hypothesis: $\mu \neq 65$

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

For this case the value of $\mu$ represent the parameter associated to the population (True average of cofee temperature)

Step-by-step explanation:

Data given and notation

$\bar X=70.2$ represent the mean height for the sample

$s$ represent the sample standard deviation for the sample

$n=20$ sample size

$\mu_o =765$ represent the value that we want to test

$\alpha$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the true mean i equal to 70.2, the system of hypothesis would be:

Null hypothesis: $\mu = 65$

Alternative hypothesis: $\mu \neq 65$

If we analyze the size for the sample is < 30 and we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

For this case the value of $\mu$ represent the parameter associated to the population (True average of cofee temperature)

3 0

3 years ago

Can someone help me pleaseeeeee​

Can someone help me pleaseeeeee