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3 years ago

Help? mathhhhhhhhhhhhhhhhhhhhhhhhhhhh

Mathematics

1 answer:

Vanyuwa [196]3 years ago

4 0

Answer:

a + 20 = 7*12 (multiplied both sides by 12)

a + 20 = 84 (calculated 7*12)

a = 84 - 20 (subtracted 20 on both sides)

a = 64 (calculated 84-20)

You might be interested in

20=v−7 what does v equal?

dedylja [7]

Answer:

Step-by-step explanation:

20=v-7

v=20+7

v=27

Hence, v equals to 27

3 0

3 years ago

Read 2 more answers

Use the graph to find the

Dmitry [639]

The y intercept is 2, because that is the value of y when it crosses the y axis.

Since the line is pointing down, it has a negative slope, and since the y value goes down 2 for every 3 x values, the slope is -2/3. You should always right the slope in rise/run form, or change in y/change in x.

Finally, write the equation in the form of y=mx+b, where m is the slope and b is the y intercept. This means the equation of the line is y=-2/3x+2.

7 0

2 years ago

A random sample of adults showed that of them have shopped at least once on the Internet. What is the (approximate) probability

Anvisha [2.4K]

Answer:

P = number of adults who have shopped at least once on the internet / number sampled adults

Step-by-step explanation:

Step 1

Let X be the number sampled adults

Let Y be the number of adults who have shopped at least once on the internet.

Let P be the probability that a randomly selected adult has shopped on the Internet.

Step 2

P = number of adults who have shopped at least once on the internet / number sampled adults

P = Y/X

An example:

If X is 1000 adults and Y is 200 adults therefore P = 200/1000 = 0.2

One can therefore infer that approximately 0.2 of the population surfs the internet at least once in a week.

5 0

3 years ago

The test scores on a 100-point test were recorded for 20 students:71 93 91 86 7573 86 82 76 5784 89 67 62 7277 68 65 75 84a. Can

Dafna11 [192]

Answer: a. Yes

b. mean = 76.65

standard deviation = 10.04

c. 76.65 ± 4.4

Step-by-step explanation:

a. Stem and leaf Plot shows the frequencies with which classes of value occur. To create this plot, we divide the set of numbers into 2 columns: stem, the left column, which contains the tens digits; leaf, the right column, which contains the unit digits.

Normal distribution is a type of distribution: it's a bell-shaped, symmetrical, unimodal distribution.

A stem and leaf plot displays the main features of the distribution. If turned on its side, we can see the shape of the data.

The figure below shows the stem and leaf plot of the 100-point test score. As we can see, when turned, the plot resembles bell-shaped distribution. So, this test scores were selected from a normal population.

b. Mean is the average number of a data set. It is calculated as the sum of all the data divided by the quantity the sample has:

mean = $\frac{\Sigma x}{n}$

For the 100-point test score:

mean = $\frac{71+93+91+...+65+75+84}{20}$

mean = 76.65

Standard Deviation determines how much the data is dispersed from the mean. It is calculated as:

$s=\sqrt{\frac{\Sigma (x-mean)^{2}}{n-1} }$

For the 100-point test score:

$s=\sqrt{\frac{[(71-76.65)+(93-76.65)+...+(84-76.65)]^{2}}{20-1} }$

s = 10.04

The mean and standard deviation of the scores are 76.65 and 10.04, respectively.

c. Confidence Interval is a range of values we are confident the real mean lies.

The calculations for the confidence interval is

mean ± $z\frac{s}{\sqrt{n} }$

where

z is the z-score for the 95% confidence interval, which is equal 1.96

Calculating interval

76.65 ± $1.96.\frac{10.04}{\sqrt{20} }$

76.65 ± 4.4

The 95% confidence interval for the average test score in the population of students is between 72.25 and 81.05.

7 0

3 years ago

What is the fraction of 0.344

Genrish500 [490]

Hello!

$\bf Answer:$

$\boxed{ \bf 0.334~=~344/100~or~43/125}$ as a fraction.

0.344 = 0.344/1

The 4 is in the thousandths place. Multiply both the numerator and the denominator by 1000.

0.344 × 1000 = 344

1 × 1000 = 1000

This gives us: 344/1000

It's fraction form can be reduced. Simply divide both the numerator and the denominator by 8:

344 ÷ 8 = 43

1000 ÷ 8 = 125

6 0

3 years ago