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3 years ago

Evaluate the expression 4ab, for a =2 and b = 5

Mathematics

2 answers:

yan [13]3 years ago

4 0

Answer:

Step-by-step explanation:

4x2=8

8x5=40

expeople1 [14]3 years ago

3 0

Answer:

Step-by-step explanation:

you do this 4(a*b)

ab is 10 so 4*ab=40

hint (if you see two variables without a symbol in between, multiply)

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A sequence can be generated by using an = a(n-1) + 3, where ai = 8 and n is a whole number greater than 1. What are the first fo

Georgia [21]

Answer:

Step-by-step explanation:

a1=8 (as given)

a2=a1+3=8+3=11

a3=a2+3=11+3=14

a4=a3+3=14+3=17

3 0

3 years ago

If 50% of a number is 60, find 5% of that number. i need it rn

zhenek [66]

Answer:

Step-by-step explanation:

if something has 60 as it's 50 percent, then 100 percent would be 120

now we have to find 5 percent of 120:

5/100 × 120= 6

3 0

3 years ago

Read 2 more answers

Hey PLEASE HELP DUE TODAY

nadya68 [22]

What the maning of that ?

4 0

3 years ago

What is the value of A+B+E? 15 17 -15 13 Thank you in advance!

ki77a [65]

Answer:

Step-by-step explanation:

∫ x² e⁻³ˣ dx = -1/27 e⁻³ˣ [Ax² + Bx + E] + C

Take derivative of both sides:

x² e⁻³ˣ = d/dx {-1/27 e⁻³ˣ [Ax² + Bx + E] + C}

x² e⁻³ˣ = -1/27 d/dx {e⁻³ˣ [Ax² + Bx + E]}

-27x² e⁻³ˣ = d/dx {e⁻³ˣ [Ax² + Bx + E]}

Use product rule to evaluate the derivative:

-27x² e⁻³ˣ = {e⁻³ˣ [2Ax + B] − 3e⁻³ˣ [Ax² + Bx + E]}

-27x² e⁻³ˣ = e⁻³ˣ {2Ax + B − 3 [Ax² + Bx + E]}

-27x² e⁻³ˣ = e⁻³ˣ [2Ax + B − 3Ax² − 3Bx − 3E]

-27x² e⁻³ˣ = e⁻³ˣ [-3Ax² + (2A − 3B) x + (B − 3E)]

-27x² = -3Ax² + (2A − 3B) x + (B − 3E)

Match the coefficients:

-27 = -3A

0 = 2A − 3B

0 = B − 3E

Solve the system of equations:

A = 9

B = 6

E = 2

Therefore, A + B + E = 17.

6 0

3 years ago

The mean of a population is 74 and the standard deviation is 16. The shape of the population is unknown. Determine the probabili

bulgar [2K]

Answer:

$P(X > 75)= 0.35402$

$P(72 < X < 75 ) = 0.2529$

$P( X < 74.7) = 0.74041$

Step-by-step explanation:

From the question we are told that

The population mean is $\mu = 74$

The population standard deviation is $\sigma = 16$

Considering question a

The sample size is n = 36

Generally the standard error of mean is mathematically represented as

$\sigma_{x} = \frac{\sigma }{\sqrt{n} }$

=> $\sigma_{x} = \frac{16}{\sqrt{36} }$

=> $\sigma_{x} = 2.67$

Generally the probability that a random sample of size 36 yielding a sample mean of 75 or more is mathematically represented as

$P(X > 75) = P( \frac{X - \mu }{ \sigma_{x}} > \frac{75 - 74}{ 2.67 } )$

$\frac{X -\mu}{\sigma } = Z (The \ standardized \ value\ of \ X )$

$P(X > 75) = P(Z > 0.3745 )$

From the z table the area under the normal curve representing 0.3745 to the right is

$P(Z > 0.3745 ) = 0.35402$

=> $P(X > 75)= 0.35402$

Considering question b

The sample size is n = 104

Generally the standard error of mean is mathematically represented as

$\sigma_{x} = \frac{\sigma }{\sqrt{n} }$

=> $\sigma_{x} = \frac{16}{\sqrt{104} }$

=> $\sigma_{x} = 1.5689$

Generally the probability that a random sample of size 104 yielding a sample mean between 72 and 75 is mathematically represented as

$P(72 < X < 75 ) = P(\frac{72 - 74 }{1.5689} < \frac{X - \mu }{\sigma_{x}} < \frac{75 - 74 }{1.5689} )$

=> $P(72 < X < 75 ) = P(-1.275 < Z < 0.375 )$

=> $P(72 < X < 75 ) = P(Z < 0.375 ) - P(Z < -1.275)$

From the z table the area under the normal curve representing -1.275 to to the left is

$P(Z < -1.275) =0.10115$

=> $P(72 < X < 75 ) = 0.35402 - 0.10115$

=> $P(72 < X < 75 ) = 0.2529$

Considering question c

The sample size is n = 217

Generally the standard error of mean is mathematically represented as

$\sigma_{x} = \frac{\sigma }{\sqrt{n} }$

=> $\sigma_{x} = \frac{16}{\sqrt{217} }$

=> $\sigma_{x} = 1.086$

Generally the probability that a random sample of size 217 yielding a sample mean of less than 74.7 is mathematically represented as

$P( X < 74.7) = P(\frac{X - \mu }{\sigma_x} < \frac{ 74.7 - 74 }{ 1.086 })$

=> $P( X < 74.7) = P(Z < 0.6446 )$

From the z table the area under the normal curve representing 0.6446 to to the left is

$P(Z < 0.6446 ) = 0.74041$

=> $P( X < 74.7) = 0.74041$

8 0

3 years ago