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3 years ago

When evaluating the expression 5x^2 for x=4 explain why 4 must be squared before multiplying by 5

Mathematics

1 answer:

fenix001 [56]3 years ago

3 0

Answer:

Order of operations

Step-by-step explanation:

4 must be squared before multiplying by 5 because of order of operations (PEMDAS). PEMDAS stands for parentheses, exponents, multiplication, division, addition, and subtraction. 4 squared is an example of an exponent and multiplying by 5 is an example of multiplication. Therefore 4 squared must come first.

When 4 is squared first, you will get an answer of 80.

When you multiply by 5 first, you will get an answer of 400.

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Maths!

Ber [7]

Answer:

(1) Variance = 4.5 and Standard deviation = 2.121.

(2) Variance = 4.5 and Standard deviation = 2.121.

(3) The effect on the measure of dispersion if each value is changed uniformly is that it remains unchanged.

Step-by-step explanation:

We are given with the following set of data below;

X $X-\bar X$ $(X-\bar X)^{2}$

5 5 - 8 = -3 9

8 8 - 8 = 0 0

10 10 - 8 = 2 4

9 9 - 8 = 1 1

6 6 - 8 = -2 4

Total 72 36

Firstly, the mean of the above data is given by;

Mean, $\bar X$ = $\frac{\sum X}{n}$

= $\frac{72}{9}$ = 8

(1)Now, the variance of the given data is;

Variance = $\frac{\sum (X-\bar X)^{2} }{n-1}$

= $\frac{36}{9-1}$ = 4.5

So, the standard deviation, (S.D.) = $\sqrt{\text{Variance}}$

= $\sqrt{4.5}$ = 2.12

(2) Now, each value is added by 2; so the new data set is given by;

X $X-\bar X$ $(X-\bar X)^{2}$

7 7 - 10 = -3 9

10 10 - 10 = 0 0

12 12 - 10 = 2 4

11 11 - 10 = 1 1

8 8 - 10 = -2 4

Total 90 36

Firstly, the mean of the above data is given by;

Mean, $\bar X$ = $\frac{\sum X}{n}$

= $\frac{90}{9}$ = 10

(1)Now, the variance of the given data is;

Variance = $\frac{\sum (X-\bar X)^{2} }{n-1}$

= $\frac{36}{9-1}$ = 4.5

So, the new standard deviation, (S.D.) = $\sqrt{\text{Variance}}$

= $\sqrt{4.5}$ = 2.12

(3) The effect on the measure of dispersion if each value is changed uniformly is that it remains unchanged as we see in the case of variance or standard deviation.

4 0

3 years ago

For brainiest:):):):):):):)

andrew-mc [135]

Answer:

15 = 0.025

16= 3 years

Step-by-step explanation:

15.

I=prt

15= (200)(r)(3)

200(3) = 600r

15 divided by 600r = 40 (0.025)

------------------------------------------------------

16.

I=prt

$t= \frac{I}{Ixp} \\t= \frac{90}{0.05x600} \\t= 3$

t= 3 years

5 0

3 years ago

Ebi, Jose, Derell, and Asami measured their heights. Ebi's height was 2.5 cm greater than Jose's height. Jose's height was 3.1 c

irga5000 [103]

Start with assigning each person with a variable to represent their height

Ebi: e
Jose: j
Derell: d
Asami: a

Ebi'd height was 2.5 cm greater than Jose's height

j + 2.5 = e

Jose's height was 3.1 cm greater than Derell's

d + 3.1 = j

Derell's height is 0.4 cm less than Asami's height

a - 0.4 = d

Ebi is 162.5 cm tall

e = 162.5

So, plug in 162.5 into any of the above equations were there is a variable of e

j + 2.5 = e

j + 2.5 = 162.5

Subtract 2.5 from both sides of the equation

j = 160 cm

Jose's height is 160 cm

Now, plug in 160 into any of the above equations where there is a j

d + 3.1 = j

d + 3.1 = 160

Subtract 3.1 from both sides of the equation

d = 156.9 cm

Derell's height 156.9 cm

so, plug in 156.9 into any of the above equations where there is a d

a - 0.4 = d

a - 0.4 = 156.9

Add 0.4 on both sides of the equation

a = 157.3 cm

Asami's height is 157.3 cm

7 0

3 years ago

Read 2 more answers

Which statements describe a parallelogram that must be a square? Select each correct answer.

Oxana [17]

That would be B, C and E.

A and D could be a rhombus.

8 0

3 years ago

Read 2 more answers

PLEASE HELP ME!!! ANSWER BOTH QUESTIONS & I WILL MARK BRAINLIEST!!!

Nataly [62]