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2 years ago

Seventh grade > EE.11 Probability of independent and dependent events NED

Mathematics

1 answer:

ella [17]2 years ago

8 0

Step-by-step explanation:

each combination of 2 specific numbers has the same probability. there is no difference in probability between the individual numbers.

remember, a probability is always desired cases over all possible cases.

we have 4 different possible outcomes every time we spin the spinner.

to get a specific number has the probability of 1/4, because we want 1 specific outcome, and have in total 4 different possibilities.

now, we spin a second time. the probability to get a specific number is again 1/4.

but, if we consider both events to be connected, when we want to know the probability to get 2 specific numbers when spinning twice, we have to multiply the individual probabilities :

1/4 × 1/4 = 1/16

so, the probability to land first on a 5, and then secondly on a 2 is 1/16.

the same as for landing first on a 3, and then on a 5.

the same as for landing first on a 4, and then on a 4 (again).

that is because the individual spin results are independent. the result of the first spin does not impact in any way the result of the second spin (in contrary to e.g. pulling multiple cards without returning the previously pulled cards).

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Can someone answer theese questions I WILL GIVE BRAINLIST and thanks and a 5 star if they are correct

hodyreva [135]

The first question I think it’s A because 1.13 is larger than 1.2
I hope this helps

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2 years ago

In a poll, 37% of the people polled answered yes to the question "Are you in favor of the death penalty for a person convicte

Kay [80]

Answer:

The number of people surveyed was 330.

Step-by-step explanation:

The (1 - α)% confidence interval for the population proportion is:

$CI=\hat p\pm z_{\alpha/2}\cdot \sqrt{\frac{\hat p(1-\hat p)}{n}}$

The margin of error for this interval is:

$MOE= z_{\alpha/2}\cdot \sqrt{\frac{\hat p(1-\hat p)}{n}}$

The information provided is:

$\hat p=0.37\\MOE=0.05\\\text{Confidence level}=0.94\\\Rightarrow \alpha=0.06$

The critical value of z for 94% confidence level is, z = 1.88.

*Use a z-table.

Compute the value of n as follows:

$MOE= z_{\alpha/2}\cdot \sqrt{\frac{\hat p(1-\hat p)}{n}}$

$n=[\frac{z_{\alpha/2}\times \sqrt{\hat p(1-\hat p)}}{MOE}]^{2}$

$=[\frac{1.88\times \sqrt{0.37(1-0.37)}}{0.05}]^{2}\\\\=(18.153442)^{2}\\\\=329.5475\\\\\approx 330$

Thus, the number of people surveyed was 330.

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2 years ago

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4ttyu88 h ghiiiUuiyy ...

frez [133]

Answer:

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3 years ago

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0.8-4x=-0.4y 6x+0.4y=4.2 Which of the following shows the system with like terms aligned? 4x - 0.4y = -0.8 6x + 0.4y = 4.2 -4x +

Brut [27]

Answer: The correct option is option third .

Explanation:

The given equation are,

$0.8-4x=-0.4y\\6x+0.4y=4.2$

In the second equation the like terms are aligned, therefore, we have to aligened only first equation.

The first equation is,

$0.8-4x=-0.4y$

Subtract 0.8 from both the sides.

$0.8-4x-0.8=-0.4y-0.8$

$-4x=-0.4y-0.8$

Add 0.4y on both the sides.

$-4x+0.4y=-0.4y-0.8+0.4y$

$-4x+0.4y=-0.8$

So, after aligned the system of equation have two equations.

$-4x+0.4y=-0.8$

$6x+0.4y=4.2$

Both equation are show in third option, So third option is correct.

3 0

2 years ago

Read 2 more answers

The federal government recently granted funds for a special program designed to reduce crime in high-crime areas. A study of the

Ksenya-84 [330]

Answer:

Step-by-step explanation:

Hello!

There was a special program funded, designed to reduce crime in 8 areas of Miami.

The number of crimes per area was recorded before and after the program was established in each area. This is an example of a paired data situation. For each are in Miami you have recorded a pair of values:

X₁: Number of crimes recorded in one of the eight areas of Miami before applying the special program.

X₂: Number of crimes recorded in one of the eight areas of Miami after applying the special program.

Area: (Before; After)

A: (14; 2)

B: (7; 7)

C; (4; 3)

D: (5; 6)

E: (17; 8)

F: (12; 13)

G: (8; 3)

H; (9; 5)

To apply a paired sample test you have to define the variable "difference":

Xd= X₁ - X₂

I'll define it as the difference between the crime rate before the program and after the program.

If the original populations have a normal distribution, we can assume that the variable defined from them will also have a normal distribution.

Xd~N(μd; σd²)

If the crime rate decreased after the special program started, you'd expect the population mean of the difference between the crime rates before and after the program started to be less than zero, symbolically μd<0

The hypotheses are:

H₀: μd≥0

H₁: μd<0

α: 0.01

$t= \frac{X[bar]_d-Mu_d}{\frac{S_d}{\sqrt{n} } } ~~t_{n-1}$

To calculate the sample mean and standard deviation of the variable difference, you have to calculate the difference between each value of each pair:

A= 14 - 2= 12

B= 7 - 7= 0

C= 4 - 3= 1

D= 5 - 6= -1

E= 17 - 8= 9

F= 12 - 13= -1

G= 8 - 3= 5

H= 9 - 5= 4

∑Xdi= 12 + 0 + 1 + (-1) + 9 + (-1) + 5 + 4= 29

∑Xdi²= 12²+0²+1²+1²+9²+1²+5²4²= 269

X[bar]d= 29/8= 3.625= 3.63

$S_d=\sqrt{\frac{1}{n-1}[sumX_d^2-\frac{(sumX_d)^2}{n} ] } = \sqrt{\frac{1}{7}[269-\frac{29^2}{8} ] } = 4.84$

$t_{H_0}= \frac{3.63-0}{\frac{4.86}{\sqrt{8} } } = 2.11$

This test is one-tailed to the left and so is the p-value, under a t with n-1= 8-1=7 degrees of freedom, the probability of obtaining a value as extreme as the calculated value is:

P(t₇≤-2.11)= 0.0364

The p-value is greater than the significance level, so the decision is to not reject the null hypothesis. Then at a 1% significance level, you can conclude that the special program didn't reduce the crime rate in the 8 designated areas of Miami.

I hope it helps!

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3 years ago