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3 years ago

Surface area of a sphere. Please help and no links please.

Mathematics

2 answers:

Mashutka [201]3 years ago

7 0

Answer:

725.46 or 725.5

Step-by-step explanation:

SA formula for Sphere is 4(pi)radius²

replace pi with 3.14

radius is 7.6 so its

3(3.14)7.6²

now I said 725.5 because you have to round up

V125BC [204]3 years ago

3 0

Answer:

725.4656 - surface area

Step-by-step explanation:

You might be interested in

If f(x) = 3x - 5, than f(2) =

Mamont248 [21]

If we substitute 2 into x it'll be:

$3x - 5 \\ 3(2) - 5 \\ 6 - 5 \\ 1$

5 0

3 years ago

O is the centroid. Find the value of x. (Sorry if u cant see the photo :/, but this is Geometry btw)

klemol [59]

Answer: x = 6

==============================================

Explanation:

The medians of a triangle meet up at the centroid in such a way that they cut each other at a ratio of 2:1, meaning that one part of the median is twice as long as the other. In this case, MO is two times longer than OP, so,

OP = 2*MO

and

MP = MO + OP

MP = MO + 2*MO .... replace OP with 2*MO

MP = 3*MO

9x-24 = 3*(x+4) ... plug in the given expressions

9x-24 = 3x+12

9x-3x = 12+24

6x = 36

x = 36/6

x = 6

8 0

3 years ago

A tennis coach took his team out for lunch and bought 8 hamburgers and 5 fries for $24. The players were still hungry so the coa

g100num [7]

The cost of 1 hamburger is $ 2.5 and cost of 1 fries is $ 0.8

<h3><u>Solution:</u></h3>

Let "f" be the cost of 1 fries

Let "h" be the cost of 1 hamburger

<em><u>Given that, tennis coach took his team out for lunch and bought 8 hamburgers and 5 fries for $24</u></em>

8 x cost of 1 hamburger + 5 x cost of 1 fries = 24

$8 \times h + 5 \times f = 24$

8h + 5f = 24 -------- eqn 1

<em><u>The players were still hungry so the coach bought six more hamburgers and two more fries for $16.60</u></em>

6 x cost of 1 hamburger + 2 x cost of 1 fries = 16.60

$6 \times h + 2 \times f = 16.60$

6h + 2f = 16.60 ------ eqn 2

<em><u>Let us solve eqn 1 and eqn 2</u></em>

Multiply eqn 1 by 2

16h + 10f = 48 ------ eqn 3

Multiply eqn 2 by 5

30h + 10f = 83 -------- eqn 4

<em><u>Subtract eqn 3 from eqn 4</u></em>

30h + 10f = 83

16h + 10f = 48

( - ) ----------------------

14h = 35

Substitute h = 2.5 in eqn 1

8(2.5) + 5f = 24

20 + 5f = 24

5f = 4

Thus cost of 1 hamburger is $ 2.5 and cost of 1 fries is $ 0.8

5 0

3 years ago

Your bookcase contains 3 history book, 5 psychology books, 2 mystery novels and 5 sci-fi books. Assuming each book has an equal

dlinn [17]

5/15

Step-by-step explanation:

8 0

3 years ago

When circuit boards used in the manufacture of compact disc players are tested, the long-run percentage of defectives is 5%. Let

vladimir1956 [14]

Answer:

a) P(X ≤ 2) = 0.87

b) P(X ≥ 5) = 0.01

c) P(1 ≤ X ≤ 4) = 0.71

d) P ( X = 0 ) = 0.28

e) σ(X) = 1.09 , E(X) = 1.25

Step-by-step explanation:

Given:

- Let X = the number of defective boards in a random sample of size n = 25, so X ~ Bin(25, 0.05)

Where, n = 25 and p = 0.05

Find:

(a) Determine P(X ≤ 2).(b) Determine P(X ≥ 5).(c) Determine P(1 ≤ X ≤ 4).(d) What is the probability that none of the 25 boards is defective?(e) Calculate the expected value and standard deviation of X.

Solution:

- The probability mass function for a binomial distribution is given by:

P ( X = x ) = nCr * (p)^r * ( 1 - p )^(n-r)

a) P(X ≤ 2):

P(X ≤ 2) = P ( X = 0 ) + P ( X = 1 ) + P ( X = 2 )

= (0.95)^25 + 25*0.05*0.95^24 + 25C2*0.05^2*0.95^23

= 0.87

b) P(X ≥ 5):

P(X ≥ 5) = 1 - [P ( X = 0 ) + P ( X = 1 ) + P ( X = 2 ) + P ( X = 3 ) + P(X=4)

= 1 - [ 0.87 + 25C3*0.05^3*0.95^22 + 25C4*0.05^4*0.95^21]

= 1 - 0.98994

= 0.01

c) P(1 ≤ X ≤ 4):

P(1 ≤ X ≤ 4) = P ( X = 1 ) + P ( X = 2 ) + P ( X = 3 ) + P(X=4)

= ( 0.87 - 0.95^25) + 0.11994

= 0.71

d) P( X = 0 )

P ( X = 0 ) = 0.95^25 = 0.28

e) E(X) & σ(X):

E(X) = n*p

E(X) = 25*0.05 = 1.25

σ(X) = sqrt ( Var (X) )

σ(X) = sqrt ( n*p*(1-p) ) = sqrt ( 25*0.05*0.95 )

σ(X) = 1.09

4 0

3 years ago