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3 years ago

5:Pretest 5 Spatial Thinking

Mathematics

1 answer:

jeyben [28]3 years ago

4 0

Given:

The coordinates of point P are (-5,4).

Point P is reflected over the x-axis.

To find:

The new coordinates after the reflection.

Solution:

If a point is reflected across the x-axis, then the rule of reflection is:

$(x,y)\to (x,-y)$

Using this rule, we get

$P(-5,4)\to P'(-5,-4)$

The new coordinates of point P after the reflection over the x-axis are (-5,-4).

Therefore, the correct option is B.

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Please help me with this

Thepotemich [5.8K]

Answer:

6,561

39,204

25,575

52.5625 - 7.5625 = 45

4 0

3 years ago

Read 2 more answers

Sum of odd numbers from 1 to 100?

Igoryamba

Series would be: 1,3,5......99

Here, a=1, d = 3-1 = 2, l = 99

l = a+(n-1)d

99 = 1+(n-1)2

98 = 2n-2

2n = 100

n = 50

Sum would be Sn = n/2 (a+l)

50/2 (1+99)

25(100) = 2500

So, your answer is 2500

4 0

3 years ago

Many elementary school students in a school district currently have ear infections. A random sample of children in two different

Marta_Voda [28]

Answer:

Step-by-step explanation:

The summary of the given data includes;

sample size for the first school $n_1$ = 42

sample size for the second school $n_2$ = 34

so 16 out of 42 i.e $x_1$ = 16 and 18 out of 34 i.e $x_2$ = 18 have ear infection.

the proportion of students with ear infection Is as follows:

$\hat p_1 = \dfrac{16}{42}$ = 0.38095

$\hat p_2 = \dfrac{18}{34}$ = 0.5294

Since this is a two tailed test , the null and the alternative hypothesis can be computed as :

$H_0 :p_1 -p_2 = 0 \\ \\ H_1 : p_1 - p_2 \neq 0$

level of significance ∝ = 0.05,

Using the table of standard normal distribution, the value of z that corresponds to the two-tailed probability 0.05 is 1.96. Thus, we will reject the null hypothesis if the value of the test statistics is less than -1.96 or more than 1.96.

The test statistics for the difference in proportion can be achieved by using a pooled sample proportion.

$\bar p = \dfrac{x_1 +x_2}{n_1 +n_2}$

$\bar p = \dfrac{16 +18}{42 +34}$

$\bar p = \dfrac{34}{76}$

$\bar p = 0.447368$

$\bar p + \bar q = 1 \\ \\ \bar q = 1 -\bar p \\ \\\bar q = 1 - 0.447368 \\ \\\bar q = 0.552632$

The pooled standard error can be computed by using the formula:

$S.E = \sqrt{ \dfrac{ \bar p \bar q}{ n_1} + \dfrac{\bar p \bar p}{n_2} }$

$S.E = \sqrt{ \dfrac{ 0.447368 * 0.552632}{ 42} + \dfrac{ 0.447368 * 0.447368}{34} }$

$S.E = \sqrt{ \dfrac{ 0.2472298726}{ 42} + \dfrac{ 0.2001381274}{34} }$

$S.E = \sqrt{ 0.01177284105}$

$S.E = 0.1085$

The test statistics is ;

$z = \dfrac{\hat p_1 - \hat p_2}{S.E}$

$z = \dfrac{0.38095- 0.5294}{0.1085}$

$z = \dfrac{-0.14845}{0.1085}$

z = - 1.368

Decision Rule: Since the test statistics is greater than the rejection region - 1.96 , we fail to reject the null hypothesis.

Conclusion: There is insufficient evidence to support the claim that a difference exists between the proportions of students who have ear infections at the two schools

5 0

3 years ago

A number,y,is 2 more than 3 times another number,x, the sum of the 2 numbers is 26. What are the two numbers?

Ivanshal [37]

Y = 2 + 3x
x + y = 26

Substitute:
x + (2 + 3x) = 26
4x + 2 = 26
4x = 24
x = 6

6 + y = 26
y = 20

3 0

3 years ago

The data set below shows prices for concert tickets in 10 major cities. Find the interquartile range (IQR) of the set. How do t

Llana [10]

Answer: IQR = 16

Step-by-step explanation:

Given the following data:

Cost of concert :

CITY : Q, R, S, T, U, V, W, X, Y, Z

Price : 35,36,42,38, 24,29,25, 44,49, 26

Interquartile range (IQR) = Q3 - Q1

Where,

Q3 = the upper quartile

Q1 = lower quartile

Rearranging the data:

24,25,26,29,35,36,38,42,44,49

Q3 = 42

Q1 = 26

IQR = (42 - 26) = 16

5 0

4 years ago