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3 years ago

Solve the quadratic equation (2x+5)(2x-5)

1 answer:

mote1985 [20]3 years ago

4 0

If you want to multiply (2*x + 5) and (2*x - 5), you can do this using the following steps:

(2*x + 5) * (2*x - 5) = 4*x^2 - 10*x + 10*x - 25 = 4*x^2 - 25

The correct result is 4*x^2 - 25.

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A random sample of 102 full-grown lobsters had a mean weight of 16 ounces and a standard deviation of 3.4 ounces. Construct a 98

pshichka [43]

Answer:

The best point estimate for a confidence interval estimating the population μ is 16 ounces.

The 98 percent confidence interval for the population mean μ is between 15.21 ounces and 16.79 ounces.

Step-by-step explanation:

We have the standard deviation for the sample, so we use the t-distribution to solve this question.

The best point estimate for a confidence interval estimating the population μ is

The sample mean, so 16 ounces.

T interval

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 102 - 1 = 101

98% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 101 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.98}{2} = 0.99$ . So we have T = 2.36

The margin of error is:

$M = T\frac{s}{\sqrt{n}} = 2.36\frac{3.4}{\sqrt{102}} = 0.79$

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 16 - 0.79 = 15.21 ounces

The upper end of the interval is the sample mean added to M. So it is 16 + 0.79 = 16.79 ounces

The 98 percent confidence interval for the population mean μ is between 15.21 ounces and 16.79 ounces.

4 0

2 years ago

Based on the Egyptian Social Pyramid, which statement below is true?

Novosadov [1.4K]

Answer:

Third Option

Step-by-step explanation:

Lets use process of elimination to find the answer to this question. It's not the first option because a scribes job was mainly in the government district as writers/record keepers meaning they don't really protect the kingdom from invasion. It's not the second options because Merchants were traders, meaning they don't make up the Pharaohs police force because all they do is sell goods to Egyptians. Then it's not fourth option because farmers, servants, and slaves make up way more then 20% of ancient Egypt. Leaving the third option meaning it's your answer.

Hope this helps.

7 0

3 years ago

M∠a=(48−x)°m∠b=(9x−38)°m∠c=90°

Pachacha [2.7K]

The question does not specify the condition that must satisfy the given angles. We assume they are the internal angles of a triangle.

Answer:

x = 10

Step-by-step explanation:

Internal Angles of a Triangle

The measure of the angles of a triangle are given as 48-x, 9x-38, and 90. Since the sum of the internal angles of a triangle is 180°:

48 - x + 9x - 38 + 90 = 180

Simplifying:

100 + 8x = 180

Subtracting 100:

8x = 180 - 100 = 80

x = 80/8

x = 10

7 0

3 years ago

Can 21 go into 30 how many times

Likurg_2 [28]

21 can go into 30 once

4 0

3 years ago

Help me with this math multiple choice question

vaieri [72.5K]

Answer: D

Step-by-step explanation: There’s a cool website called math-way all you need to do is put in the question correctly and put in how you want it solved. For example, if you want it graphed you put in Graph. PS. It’s free!!

3 0

3 years ago

Read 2 more answers