W h a t is the meaning of life?

Krissi has $14 in the bank and earns $8 a day. John has 35$ and earns $5 a day when will krissi have more money?

SOVA2 [1]

Answer: 8 days

Step-by-step explanation:

K=14+8x

J=35+5x

when K=J they will have the same amount

14+8x=35+5x

8x=21+5x

3x=21

x=7 days until they have the same amount- 8 days until she has more

5 0

2 years ago

Use the stem and leaf plot shown to answer the following question.

DENIUS [597]

16, 18, 23, 25, 26, 34, 37, 37, 40, 41, 46

37 is the upper quartile value

6 0

2 years ago

Please help me ASAP

lutik1710 [3]

9514 1404 393

Answer:

30°

Step-by-step explanation:

Consecutive interior angles are supplementary when the lines are parallel:

2x +4x = 180°

x = 180°/6

x = 30°

_____

Comment on units

A lot of times the angles are assumed to be measured in degrees. Using that assumption, x=30 (degrees). When no units are specified, the angle measure defaults to radians. In radians, x = π/6. (We rarely see problems of this nature where the angles are expected to be measured in radians. More often, we see poorly edited questions where angles need to be assumed to be measured in degrees.)

8 0

3 years ago

Find the roots of the following equations. a) 4x+9=34 b) (x-4)(x+2)=0 c) 2x^2-6x+4=0

Masteriza [31]

A. 4x + 9 = 34
 - 9 - 9
 4x = 25
 4 4
 x = 6.25

B. (x - 4)(x + 2) = 0
 x - 4 = 0 U x + 2 = 0
 + 4 + 4 - 2 - 2
 x = 4 x = -2

C. 2x² - 6x + 4 = 0
 2(x²) - 2(3x) + 2(2) = 0
2(x² - 3x + 2) = 0
 2 2
 x² - 3x + 2 = 0
 x = -(-3) +/- √((-3)² - 4(1)(2))
 2(1)
 x = 3 +/- √(9 - 8)
 2
 x = 3 +/- √(1)
 2
 x = 3 +/- 1
 2
 x = 3 + 1 U x = 3 - 1
 2 2
 x = 4 x = 2
 2 2
 x = 2 x = 1

7 0

2 years ago

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:

Data given and notation

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)

Concepts and formulas to use

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

Check for the assumptions that he sample must satisfy in order to apply the test

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.

Calculate the statistic

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

Statistical decision 

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