How many solutions does the following equation have? 2(3x+5)=5(2x-4)-4x

A simple random sample of size nequals81 is obtained from a population with mu equals 83 and sigma equals 27. (a) Describe the

Ivanshal [37]

Answer:

a) $\bar X \sim N (\mu, \frac{\sigma}{\sqrt{n}})$

With:

$\mu_{\bar X}= 83$

$\sigma_{\bar X}=\frac{27}{\sqrt{81}}= 3$

b) $z= \frac{89-83}{\frac{27}{\sqrt{81}}}= 2$

$P(Z>2) = 1-P(Z$

c) $z= \frac{75.65-83}{\frac{27}{\sqrt{81}}}= -2.45$

$P(Z$

d) $z= \frac{89.3-83}{\frac{27}{\sqrt{81}}}= 2.1$

$z= \frac{79.4-83}{\frac{27}{\sqrt{81}}}= -1.2$

$P(-1.2$

Step-by-step explanation:

For this case we know the following propoertis for the random variable X

$\mu = 83, \sigma = 27$

We select a sample size of n = 81

Part a

Since the sample size is large enough we can use the central limit distribution and the distribution for the sampel mean on this case would be:

$\bar X \sim N (\mu, \frac{\sigma}{\sqrt{n}})$

With:

$\mu_{\bar X}= 83$

$\sigma_{\bar X}=\frac{27}{\sqrt{81}}= 3$

Part b

We want this probability:

$P(\bar X>89)$

We can use the z score formula given by:

$z = \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And if we find the z score for 89 we got:

$z= \frac{89-83}{\frac{27}{\sqrt{81}}}= 2$

$P(Z>2) = 1-P(Z$

Part c

$P(\bar X$

We can use the z score formula given by:

$z = \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And if we find the z score for 75.65 we got:

$z= \frac{75.65-83}{\frac{27}{\sqrt{81}}}= -2.45$

$P(Z$

Part d

We want this probability:

$P(79.4 < \bar X < 89.3)$

We find the z scores:

$z= \frac{89.3-83}{\frac{27}{\sqrt{81}}}= 2.1$

$z= \frac{79.4-83}{\frac{27}{\sqrt{81}}}= -1.2$

$P(-1.2$

8 0

4 years ago

Abel saved 43 more nickels than dimes. After he spent 17 dimes he had twice as many nickels than dimes. How many coins did he ha

Alborosie

Answer:

180 coins

Explanation:

N = number of nickels (no nickels spent)

D = number of dimes initially saved

D' = number of dimes left after spending

1) N = D + 43

2) D' = D - 17

3) N = 2*D' = 2*(D - 17)

Set equations 1) and 3) equal to each other and solve for D:

D + 43 = 2*(D - 17)

D + 43 = 2*D - 34

D = 43 + 34 = 77

N = D + 43 = 77 + 43 = 120 nickels left

D' = D - 17 = 77 - 17 = 60 dimes left

Total coins left = 120 + 60 = 180 coins (I hope this is not too confusing for you)

8 0

3 years ago

On Tuesday Clary and Mayla both ran for two and a half hours who ran the farther distance

Ksenya-84 [330]

No one because their is no fractions Or whole numbers or even decimals to show the amount that they ran please check to see if their is any other part to this question

4 0

4 years ago

Identify the end behavior of the function f(x) = 6x^4 - 12x^3 +8x -10

goldfiish [28.3K]

Answer:

Step-by-step explanation:

This is a quartic equation with a positive coefficient for x^4 so it is shaped like an M xo ir rises to both the left and the right.

4 0

3 years ago

What is the product of 3a(8a – 6b)? 24a2 – 6b 24a2 – 6ab 24a2 – 18b2 24a2 – 18ab

pishuonlain [190]

3a(8a – 6b)
= 24a^2 - 18ab

answer is 24a2 – 18ab (the last one)

3 0

3 years ago

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