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3 years ago

The expression below is a sum of cubes. 125x^3 + 144 A. True B. False

Mathematics

2 answers:

pishuonlain [190]3 years ago

8 0

It would be false bc i just took it and it was right

lubasha [3.4K]3 years ago

3 0

Answer:

False

Step-by-step explanation:

Hey there!

If this is a sum of cubes, this means that both numbers have whole numbers as the cube root of that number

The cube root of 125 is 5

But the cube root for 144 is a decimal meaning this is not a sum of cubes

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egoroff_w [7]

Can i get brainliest if my answer is true hehehehe :p

8 0

3 years ago

Claire sat a Spanish test and a French test.

posledela

Answer:

french

Step-by-step explanation:

convert both to percentage:

1. spanish:

$\frac{27}{32} \times 100 = 84.375$

2.French:

$\frac{19}{21} \times 100 = 90.476$

therefore Claire did better in the French test

6 0

4 years ago

For his job at the hardware store, Michael distributes 2,345 packages of screws into 5 equal groups for shipping. How many packa

drek231 [11]

$\\
\text{Michael distrinutes 2345 packages of screws into 5 equal groups for shipping.}\\
\\
\text{we need to find the number of packages of screws in each group.}\\
\\
\text{so for this we use the unitary method.}\\
\\
\text{The number of packages of screws in 5 groups}=2345\\
\\
\text{so the number of packages of screws in 1 group}=\frac{2345}{5}\\
\\
=469$

Hence the number of packages of screws in each shipping box is: 469

Hence option (B) is correct.

6 0

4 years ago

Line a is parallel to line b, m∠1=2x +44, and m∠5x+38. Find the value of x.

Soloha48 [4]

$2x + 44 = 5x + 38$
$5x - 2x = 3x$
$44 = 3x + 38$
$44 - 38 = 6$
$6 = 3x$
$2 = x$

5 0

3 years ago

(43 points) In the US, 85% of the population has Rh positive blood. Suppose we take a random sample of 6 persons and let Y denot

VladimirAG [237]

Answer:

a) Binomial distribution with parameters p=0.85 q=0.15 n=6

b) 62.29%

c) 2.38%

d) See explanation below

Step-by-step explanation:

We could model this situation with a binomial distribution

$P(6;k)=\binom{6}{k}p^kq^{6-k}$

where P(6;k) is the probability of finding exactly k people out of 6 with Rh positive, p is the probability of finding one person with Rh positive and q=(1-p) the probability of finding a person with no Rh.

$\bf P(Y=k)=\binom{6}{k}(0.85)^k(0.15)^{6-k}$

The probability that Y is less than 6 is

P(Y=0)+P(Y=1)+...+P(Y=5)

Let's compute each of these terms

$P(Y=0)=P(6;0)=\binom{6}{0}(0.85)^0(0.15)^{6}=1.139*10^{-5}$

$P(Y=1)=P(6;1)=\binom{6}{1}(0.85)^1(0.15)^{5}=0.0000387281$

$P(Y=2)=P(6;2)=\binom{6}{2}(0.85)^2(0.15)^{4}=0.005486484$

$P(Y=3)=P(6;3)=\binom{6}{3}(0.85)^3(0.15)^{3}=0.041453438$

$P(Y=4)=P(6;4)=\binom{6}{4}(0.85)^4(0.15)^{2}=0.176177109$

$P(Y=5)=P(6;5)=\binom{6}{5}(0.85)^5(0.15)^{1}=0.399334781$

and adding up these values we have that the probability that Y is less than 6 is

$\sum_{i=1}^{5}P(Y=i)=0.622850484\approx 0.6229=62.29\%$

In this case is a binomial distribution with n=200 instead of 6.

p and q remain the same.

The mean of this sample would be 85% of 200 = 170.

In a binomial distribution, the standard deviation is

$s = \sqrt{npq}$

In this case

$\sqrt{200(0.85)(0.15)}=5.05$

<em>Let's approximate the distribution with a normal distribution with mean 170 and standard deviation 5.05</em>

So, the approximate probability that there are fewer than 160 persons with Rh positive blood in a sample of 200 would be the area under the normal curve to the left of 160

(see picture attached)

We can compute that area with a computer and find it is

0.0238 or 2.38%

d)<em> In order to approximate a binomial distribution with a normal distribution we need a large sample like the one taken in c).</em>

In general, we can do this if the sample of size n the following inequalities hold:

$np\geq 5 \;and\;nq \geq 5$

in our case np = 200*0.85 = 170 and nq = 200*0.15 = 30

4 0

3 years ago