Will you tell e this and i give brainleest for free not stupid bro 200 + 200=

Carlos dropped the phone he had received for his birthday and broke the screen. He knows he has to pay for the replacement himse

kiruha [24]

Answer:

????????????????

Step-by-step explanation:

what's the question

7 0

3 years ago

8(3a+5)???? please help!!!!!! ASAP!!!!

r-ruslan [8.4K]

I'm assuming your teacher wants you to distribute. If so, then you multiply the outer term 8 by each term inside (3a and 5). After that you add.

8 times 3a = 24a

8 times 5 = 40

So 8(3a+5) becomes 24a+40

We do not combine 24a and 40 as they are not like terms. So we leave 24a+40 as it is.

3 0

3 years ago

Read 2 more answers

A researcher planned a study in which a crucial step was offering participants a food reward. It was important that three food r

lbvjy [14]

Answer:

Step-by-step explanation:

Hello!

A pilot study was conducted to test if three food rewards are equally appealing to the participants.

Of 60 participants surveyed:

16 preferred cupcakes (CC)

26 preferred candy bars (CB)

18 preferred dried apricots (DA)

If the three types of food are equally appealing for the participants, you'd expect that their proportions will be equal: P(CC)=P(CB)=P(DA)= 1/3

1.

The objective of this pilot study is to test if the observed frequencies follow a theoretical model/ distribution. To analyze this, you have to apply a Chi Square Goodness to Fit test. $X^2=sum \frac{(O_i-E_i)^2}{E_i} ~~X^2_{k-1}$ Where k= number of categories of the variable.

For this example the statistical hypotheses are:

H₀: P(CC)=P(CB)=P(DA)= 1/3

H₁: At least one of the proportions isn't equal to the others.

2.

To calculate the expected frequencies for each category you have to use the formula: $E_i= n* P_i$ where Pi represents the theoretical proportion for the i category, stated in the null hypothesis.

$E_{CC}= n* P(CC)= 60*1/3= 20$

$E_{CB}= n*P(CB)= 60*1/3= 20$

$E_{DA}= n* P(DA)= 60* 1/3= 20$

3.

The cutoff or critical value indicates the beginning of the rejection region for the hypothesis test. For the Chi-Square tests, the rejection region is always one-tailed to the right, meaning that you'll reject the null hypothesis if the value of the statistic is big. For the goodness to fit test you have k-1 degrees of freedom, so the critical value will be:

Assuming α: 0.05

$X^2_{k-1;1-\alpha /2}= X^2_{2;0.975}= 7.378$

The rejection region is then X²₂ ≥ 7.378

4.

$X^2_{H_0}= \frac{(O_{CC}-E_{CC})^2}{E_{CC}} + \frac{(O_{CB}-E_{CB})^2}{E_{CB}} + \frac{(O_{DA}-E_{DA})^2}{E_{DA}} = \frac{(16-20)^2}{20} +\frac{(26-20)^2}{20} +\frac{(18-20)^2}{20}= \frac{14}{5}= 2.8$

I hope this helps!

5 0

3 years ago

Which statement about the data is true

Alina [70]

Answer:

D. A value of 0.9 is more than 2 standard deviations from the mean.

Step-by-step explanation:

A is wrong, because the standard deviation is +/-0.15 (the measure up or down from the mean)

B is wrong, because the mean is exactly 0.5

C is wrong, because 1 standard deviation up from the mean is 0.65, and 0.7 is outside of that.

7 0

3 years ago

A test is normally distributed with a mean of 70 and a standard deviation of 10. Todd scores a 55 on the test. Select the answer

Jlenok [28]

Answer:

Todd's Z-score is - 0.27

Step-by-step explanation:

Explanation:-

Step(i):-

Given data A test is normally distributed with a mean of 70 and a standard deviation of 10.

Mean of the population 'μ' = 70

Standard deviation of the Population ' σ ' = 10

let 'x' be the random variable in normally distributed

Step(ii):-

Given raw score 'x' = 55

Todd's Z-score

$Z = \frac{x-mean}{S.D}$

$Z = \frac{55-70}{55}$

Z = -0.27

Final answer:-

Todd's Z-score is - 0.27

6 0

4 years ago