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2 years ago

If x is a normal random variable with a standard deviation of 10, then 3x has a standard deviation equal to:

1 answer:

4 0

Standard deviation(σ $_{x}$ ) = √V(X) = 10
Therefore, variance of X. V(X) = 10² = 100

Variance of aX is given by,
V(aX) = a²V(X)

Therefore, variance of 3X will be,
V(3X) = 3²V(X) = 9(100) = 900

Therefore, standard deviation of 3X is,

σ $_{3x}$ = √V(3X) = √900 = 30

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11) Which situation can be represented by 17.35x > 624.60?

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Answer:

J Darren earns $17.35 per hour at his job. How many hours does he need to work in order to earn more than $624.60?

Step-by-step explanation:

You're looking for a situation in which the number 17.35 needs to be multiplied by an unknown quantity.

Scenarios F and G involve addition of 17.35 to something.

Scenario H would correspond to the inequality ...

17.65x < 624.60

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2 years ago

a woman is looking for a bigger square office. she finds an office twice the area of her square office. if the perimeter is 88ft

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Answer:

Option C is the correct answer.

Step-by-step explanation:

Perimeter of current office = 88 ft

We have perimeter = 4a , where a is the side of square.

Equating

4a = 88

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Area of current office = a x a = 22 x 22 = 484 square feet.

Area of new office is twice the area of current office.

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Last year your professor wanted to study the pattern in class grades. The following table contains a sample of grades collected

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Answer:

mean = 78.4

median = 77.5

mode = 75

This is Right - skewed (positive skewness) distribution

Step-by-step explanation:

Mean:-

The mean (average) is found by adding all of the numbers together and dividing by the number of items and it is denoted by x⁻

mean = $\frac{64+80+75+98+75}{5}$

mean (x⁻ ) = 78.4

The mean of the given data = 78.4

Median:

The median is found by ordering the set from lowest to highest and finding the exact middle.

64 ,75, 80, 98

The middle term of the given data set = $\frac{75+80}{2} =77.5$

Mode :

The mode is the most common repeated number in a data set.

64 ,75, 75, 80, 98

in data the most common number = 75

Conclusion:-

mean = 78.4

median = 77.5

mode = 75

This is Right - skewed (positive skewness) distribution

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