All categories

3 years ago

Solve the equation for x.

Mathematics

1 answer:

PIT_PIT [208]3 years ago

4 0

Get unknowns on one side and know on other side.

Divide both sides by -2
X= -7

You might be interested in

A spinner with 9 equal sections is numbered 1 through 9. The probability of spinning a 1 or a 9 is 2/9 .

USPshnik [31]

The answer would be 7/9. If the spinner has 9 sections and you want to know the probability of NOT landing on a 1 or a 9, you would subtract 2 from 9 since there are 2 numbers and 9 total.

6 0

4 years ago

Read 2 more answers

Two mechanics worked on a car. The first mechanic worked for 20 hours, and the second mechanic worked for 15 hours. Together the

posledela

Let's call x1: The rate per hour of the number one mechanic. X2: The rate per hour of mechanic number two. The first thing you should do is identify the system of equations that best describes the problem. In this case it is a system of 2 equations with two unknowns which when solved gives a total of x1 = 85 $ / h and x2 = 50 $ / h. Attached solution.

5 0

3 years ago

A coin is thrown independently 10 times to test the hypothesis that the probability of heads is 0.5 versus the alternative that

mafiozo [28]

Answer:

(a) The significance level of the test is 0.002.

(b) The power of the test is 0.3487.

Step-by-step explanation:

We are given that a coin is thrown independently 10 times to test the hypothesis that the probability of heads is 0.5 versus the alternative that the probability is not 0.5.

The test rejects the null hypothesis if either 0 or 10 heads are observed.

Let p = <u><em>probability of obtaining head.</em></u>

So, Null Hypothesis, $H_0$ : p = 0.5

Alternate Hypothesis, $H_A$ : p $\neq$ 0.5

(a) The significance level of the test which is represented by $\alpha$ is the probability of Type I error.

Type I error states the probability of rejecting the null hypothesis given the fact that the null hypothesis is true.

Here, the probability of rejecting the null hypothesis means we obtain the probability of observing either 0 or 10 heads, that is;

P(Type I error) = $\alpha$

P(X = 0/ $H_0$ is true) + P(X = 10/ $H_0$ is true) = $\alpha$

Also, the event of obtaining heads when a coin is thrown 10 times can be considered as a binomial experiment.

So, X ~ Binom(n = 10, p = 0.5)

P(X = 0/ $H_0$ is true) + P(X = 10/ $H_0$ is true) = $\alpha$

$\binom{10}{0}\times 0.5^{0} \times (1-0.5)^{10-0} +\binom{10}{10}\times 0.5^{10} \times (1-0.5)^{10-10}$ = $\alpha$

$(1\times 1\times 0.5^{10}) +(1 \times 0.5^{10} \times 0.5^{0})$ = $\alpha$

$\alpha$ = 0.0019

So, the significance level of the test is 0.002.

(b) It is stated that the probability of heads is 0.1, and we have to find the power of the test.

Here the Type II error is used which states the probability of accepting the null hypothesis given the fact that the null hypothesis is false.

Also, the power of the test is represented by (1 - $\beta$ ).

So, here, X ~ Binom(n = 10, p = 0.1)

$1-\beta$ = P(X = 0/ $H_0$ is true) + P(X = 10/ $H_0$ is true)

$1-\beta$ = $\binom{10}{0}\times 0.1^{0} \times (1-0.1)^{10-0} +\binom{10}{10}\times 0.1^{10} \times (1-0.1)^{10-10}$

$1-\beta$ = $(1\times 1\times 0.9^{10}) +(1 \times 0.1^{10} \times 0.9^{0})$

$1-\beta$ = 0.3487

Hence, the power of the test is 0.3487.

3 0

3 years ago

I really don’t get it!!

AleksAgata [21]

Answer:

The answer is b.

Step-by-step explanation:

Square root 124, you'll get 29.10, after that once you simplify it, you will get the answer and you will have to do the formula, a^2 + b^2 = c^2 since it is a triangle.

8 0

3 years ago

Read 2 more answers

Which choice shows y=3x+2 and y=3x2 correctly paired with their graphs?

Blababa [14]

Answer:

The second one

7 0

3 years ago