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3 years ago

A student earned a grade of 80% on a math test that had 20 problems . How many did he get right?

Mathematics

2 answers:

JulijaS [17]3 years ago

7 0

80/100·20=8/10·20=8·2=16 (problems he got right)

<em>Answer:16</em>

shutvik [7]3 years ago

6 0

Multiply 80 and 20 and divide by 100 and get answer of 16.

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The braking time of a car is it discrete or continuous?

Rom4ik [11]

Answer:

IT'S DISCRETE

Step-by-step explanation:

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So be grateful

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2 years ago

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A box of nails costs $2.25. A box of screws costs 1.2 times as much as the box of nails.

s2008m [1.1K]

Answer:

$2.70

Step-by-step explanation:

2.25*1.2 = 2.7

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2 years ago

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One number is 4 times as large another. The sum of their reciprocals is 45/4. Find the two numbers

Reptile [31]

Let,
the numbers be "x" and "y"
According to the question,
x = 4y ......................................................equation (1)

$\frac{1}{x} + \frac{1}{y}= \frac{45}{4}$ ...................................equation (2)

Taking equation (2)
$\frac{1}{x} + \frac{1}{y}= \frac{45}{4}$

Substituting the value of "x" from equation (1), we get,

$\frac{1}{(4y)} + \frac{1}{y}= \frac{45}{4}$

$\frac{1}{4y} + \frac{1}{y}* \frac{4}{4} = \frac{45}{4}$

$\frac{1}{4y} + \frac{4}{4y}= \frac{45}{4}$

$\frac{1+4}{4y} = \frac{45}{4}$

$\frac{5}{4y} = \frac{45}{4}$

Cross multiplying, we get,

$5*4 = 45*4y$

$20 = 180y$
<u />
$\frac{20}{180} = y$

$\frac{1}{9} = y$

$y = \frac{1}{9}$

Now,
Taking equation (1)
x = 4y
Substituting the value of "y", we get

$x = 4( \frac{1}{9} )$

$x= \frac{4}{9}$

So, the numbers are $\frac{1}{9}$ and $\frac{4}{9}$

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2 years ago

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Find the value of X. Show work!!!

barxatty [35]

Answer:

x = -10

Angle 2 = 49°

Angle 3 = 49°

Step-by-step explanation:

In the given figure, it's an isosceles triangle

so, angle 2 = angle 3

( since their opposite sides are equal )

now,

in the given triangle,

=》Angle 2 + Angle 3 + 82° = 180°

( sum of all interior angles of the triangle = 180° )

=》Angle 2 + Angle 3 = 180° - 82

=》Angle 2 + Angle 3 = 98°

=》2 × Angle 2 = 98°

( since, angle 2 = angle 3 )

=》Angle 2 = 98° / 2

=》Angle 2 = 49°

so, Angle 2 = 49° = Angle 3

now,

Angle 2 = x + 59

=》49 = x + 59

=》x = 49 - 59

=》x = -10

6 0

2 years ago

10. A manufacturer wanted to know if more coupons would be redeemed if they were mailed to the

Mandarinka [93]

Using the t-distribution, it is found that the data does not provide convincing evidence that the mean number is greater when the coupons were addressed to a female.

<h3>What are the hypothesis tested?</h3>

At the null hypothesis, it is tested if there is no difference, that is, the mean is of 0, hence:

$H_0: \mu = 0$

At the alternative hypothesis, it is tested if the mean number is greater for females, that is, the mean is greater than 0, hence:

$H_1: \mu > 0$

<h3>What is the test statistic?</h3>

The test statistic is given by:

$t = \frac{\overline{x} - \mu}{\frac{s}{\sqrt{n}}}$

The parameters are:

$\overline{x}$ is the sample mean.

$\mu$ is the value tested at the null hypothesis.

s is the standard deviation of the sample.

n is the sample size.

In this problem, the parameters are given as follows:

$\overline{x} = 1.5, \mu = 0, s = 4.75, n = 50$ .

Hence, the test statistic is given by:

$t = \frac{\overline{x} - \mu}{\frac{s}{\sqrt{n}}}$

$t = \frac{1.5 - 0}{\frac{4.75}{\sqrt{50}}}$

t = 2.23

<h3>What is the conclusion?</h3>

Considering a <em>right-tailed test</em>, as we are testing if the mean is greater than a value, with a <em>significance level of 0.01 and 50 - 1 = 49 df</em>, the critical value is given by $t^{\ast} = 2.4$ .

Since the test statistic is less than the critical value for the right-tailed test, the data does not provide convincing evidence that the mean number is greater when the coupons were addressed to a female.

More can be learned about the t-distribution at brainly.com/question/26454209

5 0

1 year ago