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3 years ago

Find the sum of 3-7i and 8+4i A. 22-8i B. 11+3i C. -22+8i D. 11-3i

Mathematics

1 answer:

Veronika [31]3 years ago

8 0

D.11-3i add the numbers 11-7i+4i

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Which of the following is equivalent to In 4x+5inx-in2xy

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2 years ago

Almost all companies utilize some type of year-end performance review for their employees. Human Resource (HR) at a university's

balu736 [363]

Answer:

The Answer is 76.

Step-by-step explanation:

Given the normal distribution " 10% of employees (rated) exemplary, 20% distinguished, 40% competent, 20% marginal, and 10% unacceptable'', we can see that exemplary employees are top 10% rated employees.

We have the formula for normal distribution:

z=(X-M)÷σ

where z is the minimum z-score for top 10% employee, X is the minimum score for top 10% employee, M is the mean of the score distribution, σ is the standard deviation of the score distribution.

The z-score we are looking for is the value "a" that separates the highest 10% from the lowest 90% i.e. P(z≤a)=0.90

If we look at z-table, corresponding value for a is 1.28155

We can now put the values in the formula:

1.28155= $\frac{X-50}{20}$

So X=(1.28155×20)+50=75.631

Therefore minimum score for exemplary employee is 76.

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2 years ago

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Answer:

f x d = d x f

The commutative property of multiplication is just the numbers switched around, but it doesn't change the product. It has to in multiplication.

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2 years ago

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I'll give brainliest to whoever shows there work. Plz answer before 2: 30 pm.

olchik [2.2K]

Answer:

1st, 3rd and 5th statements are true.

Step-by-step explanation:

We have been given a table that hows the number of cars sold each month for 5 months at two dealerships. We are asked to choose the correct statement from the given choices.

1. The mean number of cars sold in a month is the same at both dealerships.

Let us find mean sales for both dealerships.

$\text{Mean}=\frac{\text{Sum of all number of data set}}{\text{Total number in data set}}$

$\text{Mean sales for Admiral autos}=\frac{4+19+15+10+17}{5}$

$\text{Mean sales for Admiral autos}=\frac{65}{5}$

$\text{Mean sales for Admiral autos}=13$

$\text{Mean sales for Countywide Cars}=\frac{9+17+14+10+15}{5}$

$\text{Mean sales for Countywide Cars}=\frac{65}{5}$

$\text{Mean sales for Countywide Cars}=13$

We can see that mean number of cars sold at both dealerships, therefore, statement 1st is true.

2. The median number of cars sold in a month is the same at both dealerships.

Let us arrange our given data set from least to greatest.

Median sales for Admiral autos: 4, 10, 15, 17, 19.

As our data set have 5 data points, therefore, the median will be the value of 3rd data point that is 15.

Median sales for Countywide Cars: 9, 10, 14, 15, 17.

As our data set have 5 data points, therefore, the median will be the value of 3rd data point that is 14.

Since the median number of cars sold at both dealerships is different, therefore, 2nd statement is false.

3. The total number of cars sold is the same at both dealerships.

We have already seen that both dealerships sold 65 cars, therefore, 3rd statement is true.

4. The range of the number of cars sold is the same for both dealerships.

$\text{Range}=\text{The highest value- The Lowest value}$

$\text{Range of Admiral Autos}=19-4$

$\text{Range of Admiral Autos}=15$

$\text{Range of Countywide Cars}=17-9$

$\text{Range of Countywide Cars}=8$

Since the ranges of both dealerships are different, therefore, 4th statement is false.

5. The data for Admiral Autos shows greater variability.

Let us find standard deviation of both data sets.

$\sigma=\sqrt{\frac{\sum(x-\overline x)^2 }{n-1}}$

$\text{SD of Admiral Autos}=\sqrt{\frac{(4-13)^2+(19-13)^2+(15-13)^2+(10-13)^2+(17-13)^2}{5-1}}$

$\text{SD of Admiral Autos}=\sqrt{\frac{(-9)^2+(6)^2+(2)^2+(-3)^2+(4)^2}{4}}$

$\text{SD of Admiral Autos}=\sqrt{\frac{81+36+4+9+16}{4}}$

$\text{SD of Admiral Autos}=\sqrt{\frac{146}{4}}$

$\text{SD of Admiral Autos}=\sqrt{36.5}\approx 6.04$

$\text{SD of Countywide Cars}=\sqrt{\frac{(9-13)^2+(17-13)^2+(14-13)^2+(10-13)^2+(15-13)^2}{5-1}}$

$\text{SD of Countywide Cars}=\sqrt{\frac{(-4)^2+(4)^2+(1)^2+(-3)^2+(2)^2}{4}}$

$\text{SD of Countywide Cars}=\sqrt{\frac{16+16+1+9+4}{4}}$

$\text{SD of Countywide Cars}=\sqrt{\frac{46}{4}}$

$\text{SD of Countywide Cars}=\sqrt{11.5}\approx 3.39$

Since SD for Admiral Autos is 6.04 and SD for Countywide Cars is 3.39, therefore, 5th statement is true indeed.

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3 years ago

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F(x) = x2 + 3x - 7

ira [324]

Just substitute in the domain
f(-3)=9-9-7=-7
f(2)=4+6-7=3
f(5)=25+15-7=33
the range is {-7,3,33}

7 0

3 years ago

Read 2 more answers