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GuDViN [60]
2 years ago
12

You are to take a multiple-choice exam consisting of 100 questions with 2 possible responses to each question. Let x represent t

he number of correct responses on the test. A) What is your expected score on the exam?B) Compute the variance and standard deviation of x.
Mathematics
1 answer:
Elena-2011 [213]2 years ago
3 0

Answer:

50 ;

25 ;

5

Step-by-step explanation:

Given that:

Number of multiple choice questions = 100

Number of possible responses = 2

Hence, probability of success, p = 1/2 = 0.5

Using normal approximation :

The expected score = mean = n*p

Expected score (X) = 100 * 0.5 = 50

standard deviation = std(X) = √

Var(X) = n*p*q

q = 1 - p = 1 - 0.5 = 0.5

Variance = Var(X) = (100 * 0.5 * 0.5)

Var(X) = 25

Var(X) = 25

The Standard deviation (Std) = √Var(X)

Std(X) = √25

Std(X) = 5

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stich3 [128]

Answer: OPTION C

Step-by-step explanation:

There are some transformations for a function f(x). Some of them are shown below:

1. If f(x)+k, the function is shifted up "k" units.

2. If f(x)-k, the function is shifted down "k" units.

3. If f(x+k), the function is shifted left "k" units.

4. If f(x-k), the function is shifted right "k" units.

In this case you know that the function "g" is the transformation of the function "f".

Observe that the function "f" intersects the y-axis at:

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And the function "g" intersects the y-axis at:

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Therefore, since both functions are 4 units apart, you can conclude that the function "f" was shifted down 4 units to get the function "g".

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5 0
3 years ago
What is 30 divide by 4?
Sedaia [141]

Answer:

30 ÷ 4 = <em>7.5</em>

Step-by-step explanation:

This means that:

7.5 fits into 30 4 times

Example:

7.5    +   7.5     +    7.5    +     7.5

 \______\______/_______/

                    30

I hope this helps!

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7 0
3 years ago
Please help me, I know it’s not the first one but I think it’s the last one. Can somebody please confirm or deny?
GaryK [48]

Answer:

B. 2.2π m² : 3.2π m²

Step-by-step explanation:

Given:

Slant height (l) = 2.2 m

Diameter (d) = 2 m

Radius (r) = ½(2) = 1 m

Required:

Lateral area and surface area

Solution:

✔️Formula for lateral area of a cone = πrl

Plug in the values

Lateral area of the cone = π*1*2.2

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Plug in the values

Surface area of the cone = π*1(2.2 + 1)

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The answer would therefore be:

2.2π m² : 3.2π m²

7 0
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Step-by-step explanation:

3 0
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Step-by-step explanation:

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