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2 years ago

Explain how solving -7y > 161 is different from solving 7y > - 161

2 answers:

8 0

Sample response: Both inequalities use the division property to isolate the variable, y. When you divide by a negative number, like –7, you must reverse the direction of the inequality sign. When you divide by a positive number, like 7, the inequality sign stays the same. The solution to the first inequality is y > -23, and the solution to the second inequality is y <>

IRISSAK [1]2 years ago

6 0

Step-by-step explanation:

-7y > 161

7y < 161

7÷7=1

161÷7=23

y=23

7y > -161

7÷7=1

-161÷7=-23

y=-23

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What is the median of these numbers 2.4,2.8,2.3,2.9,2.9

liberstina [14]

Answer:

2.8

Step-by-step explanation:

x2.3, x2.4, 2.8, x2.9, x2.9

4 0

1 year ago

A jar contains black marbles and green marbles. Sixty percent of the marbles in the jar are green. A number generator simulates

grigory [225]

Answer: D

Step-by-step explanation:

The number generator is not fair, in most of the experiments, considerably less than 60 % of the selected marbles are green.

And if Sixty percent of the marbles in the jar are green. A number generator should simulates randomly by selecting atleast one of the 60% of green marbles from the jar

5 0

2 years ago

The heights of students at a college are normally distributed with a mean of 175 cm and a standard deviation of 6 cm. One might

frosja888 [35]

Answer:

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean = 175cm

Standard deviation = 6 cm

Percentage of students below 163 cm

163 = 175 - 2*6

So 163 is two standard deviations below the mean.

By the Empirical rule, 95% of the heights are within 2 standard deviations of the mean. The other 100-95 = 5% are more than 2 standard deviations of the mean. Since the normal distribution is symmetric, 2.5% of them are more than 2 standard deviations below the mean(so below 163cm) and 2.5% are more than two standard deviations above the mean.

2.5% of the students have heights less than 163cm.

Out of 1000

0.025*1000 = 25

25 is the answer

8 0

2 years ago

Read 2 more answers

A particle moves on the circle x2+y2=25 in the xy-plane for time t≥0. At the time when the particle is at the point (3,4), dx/dt

yaroslaw [1]

Answer:

$\displaystyle y'=-\frac{9}{2}$

Step-by-step explanation:

<u>Differentiation</u>

We have a relationship between x and y as follows:

$x^2+y^2=25$

Both variables depend on time t for t≥0.

Differentiating with respect to time:

$(x^2)'+(y^2)'=(25)'$

Applying the derivative of a power function:

$2xx'+2yy'=0$

Recall the derivative of a constant is 0.

Dividing by 2:

$xx'+yy'=0$

Solving for y':

$\displaystyle y'=-\frac{xx'}{y}$

At some specific time, we have:

x=3, y=4, dx/dt = x' = 6. Substituting:

$\displaystyle y'=-\frac{3\cdot 6}{4}$

Operating:

$\displaystyle y'=-\frac{18}{4}$

Simplifying:

$\mathbf{\displaystyle y'=-\frac{9}{2}}$

8 0

2 years ago

A company claims that its tablet computers have an average recharge time of 3 hours. Using a random sample of 50 company tablet

kondor19780726 [428]

Solution:

The Statement made by company about it's tablet computer,

Average recharge time = 3 Hours

As, to check whether the company claim is illegal or true

A random sample of 50 company tablet computers, and their recharging time is noted.

As, we have taken random sample , so standard deviation will come into consideration whether company claim is true or false.

Mean recharge time of 50 company tablet computers= 2.5 hours

Standard deviation of 50 company tablet computers= 0.3 hours

So, Mean standard deviation =

$2.5 \pm0.3\\\\ 2.5 -0.3 \leq {\text{Mean standard deviation}}\leq 2.5+0.3\\\\ 2.2\leq {\text{Mean standard deviation}}\leq 2.8$

So, Claim made by company , that its tablet computers have an average recharge time of 3 hours is Approximately true.

As , there is fluctuation of (3 hours - 2.2 hours =3-2.12=48 minutes ) and (3 hours -2.8 hours=3-2.48=12 minutes), which is not so much ,so we can believe on this company and buy the product (that is tablet computers) of this company.

7 0

2 years ago

Read 2 more answers