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Fed [463]
3 years ago
13

WILL GIVE BRAINLIST SOON AS I CAN I DONT UNDERSTAND THIS, PLZ HELP​

Mathematics
1 answer:
allochka39001 [22]3 years ago
8 0

Answer:

b = 7\sqrt{3}

Step-by-step explanation:

Since the triangle is right use the tangent ratio to solve for b

and the exact value

tan30° = \frac{1}{\sqrt{3} }, thus

tan30° = \frac{opposite}{adjacent} = \frac{7}{b} and

\frac{7}{b} = \frac{1}{\sqrt{3} } ( cross- multiply )

b = 7\sqrt{3}

You might be interested in
-4/13 divided by 20/-39​
jeka57 [31]

Answer:

I don't know sowwy :c

Step-by-step explanation:

7 0
3 years ago
2a + 9 = 4 then a = _______
Juliette [100K]

Answer:

a=\frac{-5}{2}

Step-by-step explanation:

2a+9=4

2a=4-9

2a=-5

a=\frac{-5}{2}

7 0
3 years ago
The second sample was the same size as the first, and the proportion of sales identified as organic was 0.4. How does the 95 per
enot [183]

Answer:

The summer interval is wider and has a greater point of estimate  

Step-by-step explanation:

Assuming this problem: "An environmental group wanted to estimate the proportion of fresh produce sales indentified as organic in a grocery store. In the winter, the group obtained a random sample of sales from the store and used the data to construct a 95percent z-interval for a proportion (0.087,0.133). Six months later in the summer, the group obtained a second random sample of sales from the store. The second sample was the same size as the first, and the proportion of sales identified as organic was 0.4. How does the 95 percent z-interval for a proportion constructed from the summer sample compare to the winter interval? "

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".  

The margin of error is the range of values below and above the sample statistic in a confidence interval.  

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".  

The population proportion have the following distribution

p \sim N(p,\sqrt{\frac{p(1-p)}{n}})

The confidence interval would be given by this formula

\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}

For the 95% confidence interval the value of \alpha=1-0.95=0.05 and \alpha/2=0.025, with that value we can find the quantile required for the interval in the normal standard distribution.

z_{\alpha/2}=1.96

We can find the margin of error from the interval given on this case would be:

ME= \frac{0.133-0.087}{2}=0.023

And the point of estimate for the proportion obtained would be:

\hat p = 0.133-0.023=0.11

The margin of error for the proportion interval is given by this formula:  

ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}    (a)  

And on this case we have that ME =0.023 and we are interested in order to find the value of n, if we solve n from equation (a) we got:  

n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}   (b)  

And replacing into equation (b) the values from part a we got:

n=\frac{0.11(1-0.11)}{(\frac{0.023}{1.96})^2}=710.95  

And rounded up we have that n=711

Now we know that we use the same sample size for the new confidence interval. And replacing into the confidence interval formula we got:

0.4 - 1.96 \sqrt{\frac{0.4(1-0.4)}{711}}=0.364

0.4 + 1.96 \sqrt{\frac{0.4(1-0.4)}{711}}=0.436

And the new 95% confidence interval would be given (0.364;0.436) has a width of 0.436-0.364=0.072. And the width for the previous confidence interval is 0.133-0.087= 0.046. So then the best answer is:

The summer interval is wider and has a greater point of estimate  

7 0
3 years ago
The perimeter of a rhombus is 84 inches. What is the length of each side of the rhombus? Explain
dmitriy555 [2]

Answer:

Each side of the rhombus is 21 inches

Step-by-step explanation:

A rhombus has 4 equal sides: So all sides are the same

So you take the total perimeter and divide it by 4

84/4=21

4 0
4 years ago
Complete the table for the given rule.
lions [1.4K]

The table is

x | 4 | 8 | 12
y |  1 | 2 | 3

The question is not understandable. The well-formatted question is

Complete the table for the given rule

Rule:

y=\dfrac{1}{4}x

Table:

x | 4 | 8 | 12
y |  ? | ? | ?

 

Evaluation of an algebraic expression when a specified integer is used to replace a variable is known as evaluating the expression. We use the provided number to replace the expression's variable before applying the sequence of operations to simplify the expression.

For instance

On evaluation of y= x+7  when x=3, and x=12

we get y(3) = 3 + 7 = 10 and y(12) = 12 + 7 = 19

The given equation is

y=\dfrac{1}{4}x

So, the table is

x | 4 | 8 | 12
y |  1 | 2 | 3

Learn more about evaluation here-

brainly.com/question/14677373

#SPJ10

8 0
2 years ago
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