What is 2(–7.5x + 3)

1, In a class of 80 students in Debreberhan University, 45 are good in mathematics, 15 are good in both mathematics and in Engli

Aleks [24]

Treating the data as a Venn set, it is found that:

26 students are good in mathematics only.

28 students are not good in any of the three courses.

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I am going to say that:

A is the number of students good in Math.
B is the number of students good in English.
C is the number of students good in Psychology.

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9 are good in all of the three courses.

This means that: $A \cap B \cap C = 9$

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13 are good in both mathematics and psychology

This means that:

$(A \cap C) + (A \cap B \cap C) = 13$

$(A \cap C) + 9 = 13$

$(A \cap C) = 4$

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15 are good in both mathematics and in English

This means that:

$(A \cap B) + (A \cap B \cap C) = 15$

$(A \cap B) + 9 = 15$

$(A \cap B) = 6$

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16 are good in both English and psychology

This means that:

$(B \cap C) + (A \cap B \cap C) = 16$

$(B \cap C) + 9 = 16$

$(B \cap C) = 7$

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20 are good in psychology

This means that:

$c + (A \cap C) + (B \cap C) + (A \cap B \cap C) = 20$

$c + 4 + 7 + 9 = 20$

$c = 0$

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45 are good in mathematics

This means that:

$a + (A \cap B) + (A \cap C) + (A \cap B \cap C) = 45$

$a + 6 + 4 + 9 = 45$

$a = 26$

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Question a:

$a = 26$ , which means that 26 students are good in mathematics only.

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Question b:

At least one is:

$a + (A \cap B) + (A \cap C) + (B \cap C) + (A \cap B \cap C) = 26 + 6 + 4 + 7 + 9 = 52$

Thus, 80 - 52 = 28

28 students are not good in any of the three courses.

A similar problem is given at: brainly.com/question/22003843

4 0

3 years ago

I’m confused on this one

ad-work [718]

The question is "What is the scale of the model to the actual statue"

That means you must put 2/15.

2 being the model

15 being the actual statue

Take that fraction and equal is to 1/x.

Multiply 15 to 1 and 2 to x.

In the end, to solve, you divide 15 by 2x.

The answer is X=7.5

1 : 7.5

7 0

3 years ago

The specification for the pull strength of a wire that connects an integrated circuit to its frame is 10 g or more. In a sample

Wittaler [7]

Answer:

The 95% confidence interval for the difference is (-0.1888, 0.0202).

Step-by-step explanation:

Difference between proportions:

The distribution of the difference between two proportions has mean of the difference between these proportions and standard deviation is the square root of the sum of the variances. So

In a sample of 86 units made with gold wire, 68 met the specification

This means that:

$pX = \frac{68}{86} = 0.7907$

$sX = \sqrt{\frac{0.7907*0.2093}{86}} = 0.0439$

In a sample of 120 units made with aluminum wire, 105 met the specification.

This means that:

$pY = \frac{105}{120} = 0.875$

$sY = \sqrt{\frac{0.875*0.125}{120}} = 0.0302$

Difference:

$p = pX - pY = 0.7907 - 0.875 = -0.0843$

$s = \sqrt{sX^2 + sY^2} = \sqrt{0.0439^2+0.0302^2} = 0.0533$

Confidence interval:

$p \pm zs$

In which z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ , with $\alpha$ being 1 subtracted by the confidence level.

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

Lower bound of the interval:

$p - zs = -0.0843 - 1.96*0.0533 = -0.1888$

Upper bound of the interval:

$p + zs = -0.0843 + 1.96*0.0533 = 0.0202$

The 95% confidence interval for the difference is (-0.1888, 0.0202).

6 0

3 years ago

Your friend attempted to factor an expression as shown. Find the error in your friends work. Then factor the expression correctl

loris [4]

Answer:

Third step is incorrect. The correct factored form is (x-1)(2x-5).

Step-by-step explanation:

The given expression is

$2x^2-7x+5$

We need to find the factored form of this expression.

Step 1: Given

$2x^2-7x+5$

Step 2: Splitting the middle term method, the middle term can be written as (-5x-2x).

$2x^2-5x-2x+5$

$(2x^2-5x)+(-2x+5)$

Step 3: Taking out common factors from each parenthesis.

$x(2x-5)-1(2x-5)$

Step 4: Taking out common factors.

$(x-1)(2x-5)$

Therefore, the third step is incorrect. The correct factored form is (x-1)(2x-5).

3 0

3 years ago

Evaluate 2/3p + 3 when p = 3/5=

erica [24]

Answer:

so 2/3X 3/5 + 3

10 + 9 / 15 by LCM method

so 19/15 + 3 = 19/15 + 45/15 = 64/15

hope it helps

Step-by-step explanation:

8 0

3 years ago

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