Ask question

Ask question

All categories

2 years ago

8

A school psychologist wants to test the effectiveness of a new method of teaching . She recruits -grade students and randomly d

ivides them into two groups. Group 1 is taught by means of the new method, while group 2 is taught by traditional methods. The same teacher is assigned to teach both groups. At the end of the year, an achievement test (graded on a scale from 1-10) is administered and the results of the two groups are compared. Complete parts (a) through (i) below.

2 answers:

kogti [31]2 years ago

7 0

Answer:

you didn't show us what were a and i

Step-by-step explanation:

but if your looking for a controlled experiment and manipulated variable then the controlled experiment is the two groups and then the manipulated variable is the way the students learn

pav-90 [236]2 years ago

5 0

Answer:

"is" (and any subsequent words) was ignored because we limit queries to 32 words.

You might be interested in

The 18 faculty members in a college math department range in age from 32 to 68. A stem plot follows: The first and third quartil

valentina_108 [34]

Answer:

$Q_{1}=39, \:and\: Q_{3}=58$

Step-by-step explanation:

1) This Stem and Leaf plot works like a Histogram. Completing the question, check below the Stem plot. Look the data out of the Stem plot and within (in the graph below)

32, 34 , 38 , 39 , 39 , 40 , 43 , 45 , 46 , 49 , 53 , 54 , 57 , 58 , 59 , 59 , 63 , 68

2) Notice how the first digit is on the Stem column (check below)

3) To find the first and Third Quartiles

Let's use the formulas to find the position, then the value. As it follows:

$Q_3=\frac{3}{4}(n+1) \Rightarrow Q_3=\frac{3}{4}(18+1) Q_3=14.25 \approx14th =58$

$Q_1=\frac{(n+1)}{4} \Rightarrow Q_1=4.75 th \approx Q_1 =5th =39$

4 0

3 years ago

Suppose y varies directly with x. If y = –20 when x = 2, find y when x = 14

Natasha_Volkova [10]

Answer:

y = -140

Step-by-step explanation:

Y varies directly with x

y = kx

We know y = -20 when x =2, we can solve for k

-20 = k*2

Divide each side by 2

-20/2= 2k/2

-10 =k

y = -10x

Now we want to find y when x = 14

y = -10 *14

y = -140

3 0

3 years ago

Read 2 more answers

A survey was conducted in the United Kingdom, where respondents were asked if they had a university degree. One question asked,

katovenus [111]

Answer:

$z=\frac{0.121-0.0892}{\sqrt{0.101(1-0.101)(\frac{1}{373}+\frac{1}{639})}}=1.620$

$p_v =2*P(Z>1.620)=0.105$

If we compare the p value and using any significance level for example $\alpha=0.05$ always $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can say the the two proportions are not statistically different at 5% of significance

Step-by-step explanation:

Data given and notation

$X_{1}=45$ represent the number of correct answers for university degree holders

$X_{2}=57$ represent the number of correct answers for university non-degree holders

$n_{1}=373$ sample 1 selected

$n_{2}=639$ sample 2 selected

$p_{1}=\frac{45}{373}=0.121$ represent the proportion of correct answers for university degree holders

$p_{2}=\frac{57}{639}=0.0892$ represent the proportion of correct answers for university non-degree holders

z would represent the statistic (variable of interest)

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

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the proportions are different between the two groups, the system of hypothesis would be:

Null hypothesis: $p_{1} = p_{2}$

Alternative hypothesis: $p_{1} \neq p_{2}$

We need to apply a z test to compare proportions, and the statistic is given by:

$z=\frac{p_{1}-p_{2}}{\sqrt{\hat p (1-\hat p)(\frac{1}{n_{1}}+\frac{1}{n_{2}})}}$ (1)

Where $\hat p=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{45+57}{373+639}=0.101$

Calculate the statistic

Replacing in formula (1) the values obtained we got this:

$z=\frac{0.121-0.0892}{\sqrt{0.101(1-0.101)(\frac{1}{373}+\frac{1}{639})}}=1.620$

Statistical decision

For this case we don't have a significance level provided $\alpha$ , but we can calculate the p value for this test.

Since is a one side test the p value would be:

$p_v =2*P(Z>1.620)=0.105$

If we compare the p value and using any significance level for example $\alpha=0.05$ always $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can say the the two proportions are not statistically different at 5% of significance

7 0

3 years ago

Endent Practice

Vikki [24]

Answer:

Part A: The unit that would be best to describes the situations is to the mile

Part B: 4 significant figures

Part C: 1,450 miles

Part D: He is not correct

Step-by-step explanation:

Part A: By unit conversion, we have;

1 mile = 1,760 yards

Given that the distance from Ottawa, Canada to Jackson Mississippi is 2,552,000 yards it would best simplified into miles

Part B: The number of significant digits in the reporters estimate are the non-zero digits before the zeros in the number figure which are 2, 5, 5, and 2 or 4 significant figures

Part C: 2,552,000 yards = 2,552,000 yards/(1,760 yards/mile) = 1,450 miles

Part D: Given that the distance from Jackson to Tucson = 7,159,680 feet, we have;

1 mile = 5,280 feet

Therefore;

7,159,680 feet = 7,159,680 feet/(5,280 feet/mile) = 1,356 miles

Therefore, the claim that the distance from Jackson to Tucson which is 1,356 miles is further than the distance from Ottawa, Canada to Jackson Mississippi which is 1,450 miles is not correct because;

The distance from Jackson to Tucson 1,356 miles $\ngtr$ 1,450 miles which is the distance from Jackson to Ottawa

6 0

3 years ago

The volume of a rectangular prism is represented by the function x3 + 11x2 + 20x – 32. The width of the box is x – 1 while the h

Oksi-84 [34.3K]

we know that

the volume of a rectangular prism is equal to

$V=L*W*H$

where

L is the length of the box

W is the width of the box

H is is the height of the box

in this problem we have

$V=x^{3\ }+11x^2+20x-32$

$W=x-1$

$H=x+8$

$L=?$

<u>Find the length of the box</u>

Using a graph tool-------> we will determine the roots of the equation of volume

see the attached figure

the roots are

$x=-8\\x=-4\\ x=1$

so

$x^{3\ }+11x^2+20x-32=(x+8)*(x+4)*(x-1)$

therefore

<u>the answer is</u>

the length of the box is equal to $(x+4)$

8 0

3 years ago

Read 2 more answers