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marusya05 [52]
2 years ago
13

The admissions officer at a small college compares the scores on the Scholastic Aptitude Test (SAT) for the school's in-state an

d out-of-state applicants. A random sample of 18 in-state applicants results in a SAT scoring mean of 1150 with a standard deviation of 36. A random sample of 12 out-of-state applicants results in a SAT scoring mean of 1113 with a standard deviation of 54. Using this data, find the 95% confidence interval for the true mean difference between the scoring mean for in-state applicants and out-of-state applicants. Assume that the population variances are not equal and that the two populations are normally distributed.
Find the point estimate that should be used in constructing the confidence interval.
Mathematics
1 answer:
fredd [130]2 years ago
6 0

Answer:

37

Step-by-step explanation:

Here, we have two different samples, hence, to obtain the confidence interval, we use the relation for the confidence interval for two sample means ;

(x1 - x2) ± Margin of error

Where, (x1 - x2) = point estimate of the sample mean, this is the difference in mean of the two samples.

From the question ;

x1 = 1150 ; x2 = 1113

Hence, the point estimate is : (1150 - 1113) = 37

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spencer is on a mountain 11,224 feet above sea level. Heidi is on a submarine 3703 feet below sea level in a direct line below S
Alex
Since heidi is on a submarine 3703 below, we could say that she's -3703 and spencer is 11,224. 11224-(-3703)=14927
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3 years ago
A book with 650 pages has 3 pages with diagrams.
Mrac [35]

The pages that have diagrams is an illustration of proportions

0.46% pages have diagrams

<h3>How to determine the percentage</h3>

The given parameters are:

Total = 650 pages

Diagrams = 3 pages

The percentage of page that has diagram is then calculated as:

Diagram\% = \frac{Diagrams}{Total} * 100\%

So, we have:

Diagram\% = \frac{3}{650} * 100\%

Evaluate the product

Diagram\% = \frac{300}{650} \%

Divide

Diagram\% = 0.46 \%

Hence, 0.46% pages have diagrams

Read more about proportions at:

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2 years ago
Please help with problems 2-6
Airida [17]

Answer:

3. 20/20

4. 45/21

5. 7/14

6. 3 to 1

I hope this helps!

4 0
2 years ago
(a) Let R = {(a,b): a² + 3b &lt;= 12, a, b € z+} be a relation defined on z+)
grin007 [14]

Answer:

R is an equivalence relation, since R is reflexive, symmetric, and transitive.

Step-by-step explanation:

The relation R is an equivalence if it is reflexive, symmetric and transitive.

The order to options required to show that R is an equivalence relation are;

((a, b), (a, b)) ∈ R since a·b = b·a

Therefore, R is reflexive

If ((a, b), (c, d)) ∈ R then a·d = b·c, which gives c·b = d·a, then ((c, d), (a, b)) ∈ R

Therefore, R is symmetric

If ((c, d), (e, f)) ∈ R, and ((a, b), (c, d)) ∈ R therefore, c·f = d·e, and a·d = b·c

Multiplying gives, a·f·c·d = b·e·c·d, which gives, a·f = b·e, then ((a, b), (e, f)) ∈R

Therefore R is transitive

From the above proofs, the relation R is reflexive, symmetric, and transitive, therefore, R is an equivalent relation.

Reasons:

Prove that the relation R is reflexive

Reflexive property is a property is the property that a number has a value that it posses (it is equal to itself)

The given relation is ((a, b), (c, d)) ∈ R if and only if a·d = b·c

By multiplication property of equality; a·b = b·a

Therefore;

((a, b), (a, b)) ∈ R

The relation, R, is reflexive.

Prove that the relation, R, is symmetric

Given that if ((a, b), (c, d)) ∈ R then we have, a·d = b·c

Therefore, c·b = d·a implies ((c, d), (a, b)) ∈ R

((a, b), (c, d)) and ((c, d), (a, b)) are symmetric.

Therefore, the relation, R, is symmetric.

Prove that R is transitive

Symbolically, transitive property is as follows; If x = y, and y = z, then x = z

From the given relation, ((a, b), (c, d)) ∈ R, then a·d = b·c

Therefore, ((c, d), (e, f)) ∈ R, then c·f = d·e

By multiplication, a·d × c·f = b·c × d·e

a·d·c·f = b·c·d·e

Therefore;

a·f·c·d = b·e·c·d

a·f = b·e

Which gives;

((a, b), (e, f)) ∈ R, therefore, the relation, R, is transitive.

Therefore;

R is an equivalence relation, since R is reflexive, symmetric, and transitive.

Based on a similar question posted online, it is required to rank the given options in the order to show that R is an equivalence relation.

Learn more about equivalent relations here:

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4 0
2 years ago
Work out<br> (9×10²)+(7×10³)<br> State your answer in standard form
Sunny_sXe [5.5K]

Answer:

(9×10×10)+(7×10×10)

900+700

1600

1.6×10^3

4 0
3 years ago
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