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3 years ago

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keiko, chang, and scott sent a total of 130 text messages over their cell phones during the weekend. Scott sent 10 fewer message

s than Keiko. Chang sent 4 times as many messages as scott. How many messages did they each send?

1 answer:

Olenka [21]3 years ago

8 0

Keiko sent 30 text messages Scott sent 20 text messages chang sent 80

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If A is a 3×3 singular matrix such that λ1=1−i is an eigenvalue of A, then the other eigenvalues of A are 0,1+i

astra-53 [7]

Answer:

1 + i

Step-by-step explanation:

Given that A is a 3 * 3 singular matrix

one of its eigenvalue ( λ1 ) = 1 - i

Given that the determinant of a singular matrix is = 0

therefore the second eigen value ( λ2 ) = 1 + i

1 - i + 1 + i = 0

5 0

2 years ago

I know it's late but im having trouble in math.I need an exper to help for BRAINLEST and extra points

frez [133]

Answer:

B'(- 2, 2 )

Step-by-step explanation:

Given the translation rule (x, y ) → (x + 3, y - 2 )

This means add 3 to the original x- coordinate and subtract 2 from the original y- coordinate, that is

B(- 5, 4 ) → B'(- 5 + 3, 4 - 2 ) → B'(- 2, 2 )

8 0

2 years ago

George wrote an integer. The opposite of George’s integer is -53. Which of these statements about George’s integer must be true?

vlabodo [156]

The George's integer must be true for option D)I and IV.

What is integer?

A full number (not a fraction) that can be positive, negative, or zero is called an integer . -5, 1, 5, 8, 97, and 3, 043 are some examples of integers. 1.43, 1 3/4, 3.14, and other numbers are examples of non-integer numbers. Integer, which means full or whole in Latin, is the root of the English term integer. A particular category of numbers called integers includes zero, positive numbers, and negative numbers. All whole numbers, both negative and positive, and 0 are considered integers.

Here the opposite of George integer is -53.

We know that opposite value of x is -x.

Then George integer is 53.

George integer must be true for The given options I. the integer is 53 and IV.The integer has absolute value of 53.

Therefore the correct option is D) I and IV.

To learn more about integer refer the below link

brainly.com/question/13723636

#SPJ9

5 0

10 months ago

Please help for this question

kogti [31]

First you need to subtract the 29 and the 8 - equals 21
Then you subtract 7 and 4- equals 3
Lastly divide 21 and 3 and get the answer which is 7
Hope this helps.

8 0

2 years ago

Read 2 more answers

In a recent year, a poll asked 2362 random adult citizens of a large country how they rated economic conditions. In the poll,

Harman [31]

Answer:

a) The 99% confidence interval is given by (0.198;0.242).

b) Based on the p value obtained and using the significance level assumed $\alpha=0.01$ we have $p_v>\alpha$ so we can conclude that we fail to reject the null hypothesis, and we can said that at 1% of significance the proportion of people who are rated with Excellent/Good economy conditions not differs from 0.24. The interval also confirms the conclusion since 0.24 it's inside of the interval calculated.

c) $\alpha=0.01$

Step-by-step explanation:

<em>Data given and notation </em>

n=2362 represent the random sample taken

X represent the people who says that they would watch one of the television shows.

$\hat p=\frac{X}{n}=0.22$ estimated proportion of people rated as Excellent/Good economic conditions.

$p_o=0.24$ is the value that we want to test

$\alpha$ represent the significance level

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest) <em> </em>

<em>Concepts and formulas to use </em>

We need to conduct a hypothesis in order to test the claim that 24% of people are rated with good economic conditions:

Null hypothesis: $p=0.24$

Alternative hypothesis: $p \neq 0.24$

When we conduct a proportion test we need to use the z statistic, and the is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

Part a: Test the hypothesis

<em>Check for the assumptions that he sample must satisfy in order to apply the test </em>

a)The random sample needs to be representative: On this case the problem no mention about it but we can assume it.

b) The sample needs to be large enough

np = 2362x0.22=519.64>10 and n(1-p)=2364*(1-0.22)=1843.92>10

Condition satisfied.

<em>Calculate the statistic</em>

Since we have all the info requires we can replace in formula (1) like this:

$z=\frac{0.22 -0.24}{\sqrt{\frac{0.24(1-0.24)}{2362}}}=-2.28$

The confidence interval would be given by:

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

The critical value using $\alpha=0.01$ and $\alpha/2 =0.005$ would be $z_{\alpha/2}=2.58$ . Replacing the values given we have:

$0.22 - (2.58)\sqrt{\frac{0.22(1-0.22)}{2362}}=0.198$

$0.22 + (2.58)\sqrt{\frac{0.22(1-0.22)}{2362}}=0.242$

So the 99% confidence interval is given by (0.198;0.242).

Part b

<em>Statistical decision </em>

P value method or p value approach . "This method consists on determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.

The significance level provided is $\alpha=0.01$ . The next step would be calculate the p value for this test.

Since is a bilateral test the p value would be:

$p_v =2*P(z$

So based on the p value obtained and using the significance level assumed $\alpha=0.01$ we have $p_v>\alpha$ so we can conclude that we fail to reject the null hypothesis, and we can said that at 1% of significance the proportion of people who are rated with Excellent/Good economy conditions not differs from 0.24. The interval also confirms the conclusion since 0.24 it's inside of the interval calculated.

Part c

The confidence level assumed was 99%, so then the signficance is given by $\alpha=1-confidence=1-0.99=0.01$

6 0

2 years ago