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2 years ago

Simplify the expression. 28 + 4 2 A. 9 B. 11 C. 16 D. 22

Mathematics

2 answers:

padilas [110]2 years ago

8 0

Answer:

C) 16

Step-by-step explanation:

$\dfrac{28+4}{2}=\dfrac{32}{2}=16$

Andrew [12]2 years ago

6 0

$\\ \rm\hookrightarrow \dfrac{28+4}{2}$

Break

$\\ \rm\hookrightarrow \dfrac{28}{2}+\dfrac{4}{2}$

Solve

$\\ \rm\hookrightarrow 14+2$

$\\ \rm\hookrightarrow 16$

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Anais bought yards of ribbon. she had feet inches of ribbon left after trimming some curtains. how many inches of ribbon did ana

castortr0y [4]

Anais bought 2 1/2 yards of ribbon. She had 2 feet 8 inches of ribbon left after trimming some curtains. Anais uses 58 inches of ribbon to trim the curtains.

What is Unit Conversion?

Conversion of one unit to another unit of measurement for the same quantity using multiplication/division by conversion factors is known as unit conversion.
The units are expressed using scientific notation and converted into numerical values as per the quantities.

Anais bought 2 1/2 yards of ribbon.

And she had 2 feet 8 inches left after trimming some curtains.

The first thing to do is to convert all units to inches;

From standard conversion rate.

1 yard = 36 inches

As such 2 1/2 yards of ribbon in inches will be:

= 2 1/2 × 36 inches

= 5/2 × 36 inches

= 5 × 18 inches

= 90 inches of ribbon bought.

Similarly, since 1 foot = 12 inches.

The amount of curtains left after trimming is:

= ( ( 2 × 12 ) + 8 )inches

= (24 + 8) inches

= 32 inches

If Anais bought 90 inches of ribbon and she had 32 inches of ribbon left after trimming some curtains.

It implies that the number of inches of ribbon that Anais used is:

= 90 inches - 32 inches

= 58 inches

Therefore, we can conclude that Anais used 58 inches of ribbon.

Learn more about Unit Conversion

brainly.com/question/2495501

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The complete question is-

Anais bought 2 1/2 yards of ribbon. She had 2 feet 8 inches of ribbon left after trimming some curtains. How many inches of ribbon did Anais use to trim the curtains?

Anais used _____ inches of ribbon.

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1 year ago

2. What are the measures of

hodyreva [135]

Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.

To answer the above question based on the image, the answer is EBG=45; EBG is acute. EBC=100; EBC is obtuse

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3 years ago

Which of the following expressions represents the statement below?

exis [7]

Option D. 2(n + 9) is the right answer

Step-by-step explanation:

The word problems are converted into mathematical problems to solve simply.

for the given problem

"two times the sum of a number and 9"

Let n be a number then

when there is and between two things they are performed first then next operation is performed so

the sum of a number and 9

$n+9$

Then

two times the sum of a number and 9

$2(n+9)$

Hence,

Option D. 2(n + 9) is the right answer

Keywords: Mathematical notation

Learn more about mathematical notation at:

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5 0

3 years ago

A red marble is selected at random from a bag containing 2 blues and 9 red marbles and is not replaced.the probability that a se

meriva

Answer:

So the probability of drawing a second red marble is 8 out 10 or 0.8.

Step-by-step explanation:

It seems to me that if one red marble is already gone, there are 8 red marbles left out of a total of 10 marbles.

So the probability of drawing a second red marble is 8 out 10 or 0.8.

3 0

2 years ago

Read 2 more answers

A sample of 200 observations from the first population indicated that x1 is 170. A sample of 150 observations from the second po

igor_vitrenko [27]

Answer:

a) For this case the value of the significanceis $\alpha=0.05$ and $\alpha/2 =0.025$ , we need a value on the normal standard distribution thataccumulates 0.025 of the area on each tail and we got:

$z_{\alpha/2} =1.96$

If the calculated statistic $|z_{calc}| >1.96$ we can reject the null hypothesis at 5% of significance

b) Where $\hat p=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{170+110}{200+150}=0.8$

c) $z=\frac{0.85-0.733}{\sqrt{0.8(1-0.8)(\frac{1}{200}+\frac{1}{150})}}=2.708$

d) Since the calculated value satisfy this condition 2.708>1.96 we have enough evidence at 5% of significance that we have a significant difference between the two proportions analyzed.

Step-by-step explanation:

Data given and notation

$X_{1}=170$ represent the number of people with the characteristic 1

$X_{2}=110$ represent the number of people with the characteristic 2

$n_{1}=200$ sample 1 selected

$n_{2}=150$ sample 2 selected

$p_{1}=\frac{170}{200}=0.85$ represent the proportion estimated for the sample 1

$p_{2}=\frac{110}{150}=0.733$ represent the proportion estimated for the sample 2

$\hat p$ represent the pooled estimate of p

z would represent the statistic (variable of interest)

$p_v$ represent the value for the test (variable of interest)

$\alpha=0.05$ significance level given

Concepts and formulas to use

We need to conduct a hypothesis in order to check if is there is a difference between the two proportions, the system of hypothesis would be:

Null hypothesis: $p_{1} = p_{2}$

Alternative hypothesis: $p_{1} \neq p_{2}$

We need to apply a z test to compare proportions, and the statistic is given by:

$z=\frac{p_{1}-p_{2}}{\sqrt{\hat p (1-\hat p)(\frac{1}{n_{1}}+\frac{1}{n_{2}})}}$ (1)

a.State the decision rule.

For this case the value of the significanceis $\alpha=0.05$ and $\alpha/2 =0.025$ , we need a value on the normal standard distribution thataccumulates 0.025 of the area on each tail and we got:

$z_{\alpha/2} =1.96$

If the calculated statistic $|z_{calc}| >1.96$ we can reject the null hypothesis at 5% of significance

b. Compute the pooled proportion.

Where $\hat p=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{170+110}{200+150}=0.8$

c. Compute the value of the test statistic.

z-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

Replacing in formula (1) the values obtained we got this:

$z=\frac{0.85-0.733}{\sqrt{0.8(1-0.8)(\frac{1}{200}+\frac{1}{150})}}=2.708$

d. What is your decision regarding the null hypothesis?

Since the calculated value satisfy this condition 2.708>1.96 we have enough evidence at 5% of significance that we have a significant difference between the two proportions analyzed.

5 0

2 years ago