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2 years ago

The probability of a student scoring 75% in class work is 0.64, and the probability of a student scoring 85% is 0.45.

Mathematics

2 answers:

Tresset [83]2 years ago

6 0

Answer: The probability of a student scoring 75%, given that they have already scored 85% in class work is 1.

Step-by-step explanation: Given,

$P(A)=0.64$

and

$P(B)=0.45$ .

Also,

If the student already scored 85%, the it is sure that he/she will definitely score 75%. Hence, the statement that the probability of a student scoring 75% in a class work, given that they already scored 85% is 1 is a true statement.

So, the second statement is true.

zhenek [66]2 years ago

6 0

So basically, if a student scored 85 %, it sure scored 75 % too

So the true statement based on the scenario is : Event A and B are not independent because P(A|B) ≠ P (A)

hope this helps

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The probability that Edward purchases a video game from a store is 0.67 (event A), and the probability that Greg purchases a vid

Stolb23 [73]

Easy! The answer is B!

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2 years ago

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Un globo busca aterrizar en medio de dos ciudades A y B, cuya distancia entre si es de 200 km. Si se mide el ángulo de elevación

scoundrel [369]

Answer:

$h \approx 59.898\,km$

Step-by-step explanation:

El diagrama trigonométrico que representa el enunciado es incluido abajo como adjunto. Las siguientes relaciones trigonométricas describen la localización del globo. (The trigonometric diagram representing the statement is included below as attachment. The following trigonometric relations describes the location of the balloon):

$\tan 27^{\circ} = \frac{h}{x}$

$\tan 36^{\circ} = \frac{h}{200-x}$

A continuación, se obtiene la distancia horizontal: (The horizontal distance is obtained hereafter):

$x \cdot \tan 27^{\circ} = (200-x)\cdot \tan 36^{\circ}$

$x \cdot (\tan 27^{\circ} + \tan 36^{\circ})= 200\cdot \tan 36^{\circ}$

$x = \frac{200\cdot \tan 36^{\circ}}{\tan 27^{\circ}+ \tan 36^{\circ}}$

$x \approx 117.557\,km$

La altura aproximada del globo es (The approximated height of the globe is):

$h = x\cdot \tan 27^{\circ}$

$h \approx 59.898\,km$

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2 years ago

Substitute the values for a, b, and c into b2 – 4ac to determine the discriminant. Which quadratic equations will have two real

adoni [48]

Step-by-step explanation

<h3>Prerequisites:</h3>

$b^2 - 4ac = 0 \Rightarrow 1 solution$

$b^2 - 4ac > 0 \Rightarrow 2 solutions$

$b^2 - 4ac < 0 \Rightarrow No\ real\ solutions$

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$4x^2-3x-1 = 0$

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$x^2-2x-8 = 0$

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$3x^2+5x+3 = 0$

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2 years ago

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A process that produces bottles of shampoo, when operating correctly, produces bottles whose contents weight, on average, 20 oun

valentinak56 [21]

Answer:

a. Descriptive statistics for the sample.

n= 9

mean X[bar]= 20.36

median Me= 20.30

min: 19.70

max: 21.40

standad deviation S= 0.61

b. 95% Confidence interval [19.88; 20.83]

c. Decision: Support H₀

Step-by-step explanation:

Hello!

I don't have excel so I cannot install PHstat, I've used a statistic software called Infostat for the calculations.

There was a random sample of 9 bottles of shampoo taken to test if the process is operating correctly. If it is, the bottles should weight on average 20 ounces (this would be our study parameter)

The study variable is X: the weight of a bottle of shampoo.

X~N(μ;σ²)

Descriptive statistics for the sample.

n= 9

mean X[bar]= 20.36

median Me= 20.30

min: 19.70

max: 21.40

standad deviation S= 0.61

b. 95% Confidence interval.

Since the variable has a normal distribution and the population variance is unknown, the statistic to use to construct this interval is the Students t:

X[bar] ± $t_{n-1; 1- \alpha /2}$ * (S/√n)

20.36 ± $t_{8; 0.975}$ * (0.61/√9)

[19.88; 20.83]

c. You have to test the hypothesis that the production is operating correctly, if it is so, then:

H₀: μ = 20

H₁: μ ≠ 20

α: 0.05

The statistic value is t $_{H0}$ = 1.74

p-value: 0.1198

When you use the p-value to decide on a statistical hypothesis, you should always contrast it with the level of significance using the following rule:

If p-value ≤ α, then you reject the null hypothesis.

If p-value > α, then you do not reject the null hypothesis.

Since the p-value is greater than the significance level, you do not reject the null hypothesis. This means that the average weight of the shampoo bottles is 20 ounces, i.e. the process is operating correctly.

I hope it helps!

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1 year ago

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Marysya12 [62]

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Mixed numbers that are 1/3 apart and are between 0 and 2
could be (1-1/3) and (1-2/3).
They could also be (1-1/6), (1-1/2), and (1-5/6) .

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2 years ago