All categories

2 years ago

Which of the following options will definitely balance the third scale?

Mathematics

1 answer:

mel-nik [20]2 years ago

6 0

Answer:

I'd say b... But I'm not very confident about it.. Let me know if it's right.

You might be interested in

Can someone help me on this question?

notsponge [240]

Answer:

x = 19.6

Step-by-step explanation:

By applying cosine rule in ΔBCD,

cos(30)° = $\frac{\text{Adjacent side}}{\text{Hypotenuse}}$

= $\frac{BC}{BD}$

$\frac{\sqrt{3}}{2}=\frac{BC}{16}$

BC = $8\sqrt{3}$

Now, by applying sine rule in ΔBAC,

sin(45)° = $\frac{\text{Opposite side}}{\text{Hypotenuse}}$

$\frac{1}{\sqrt{2}}=\frac{AB}{BC}$

$\frac{1}{\sqrt{2}}=\frac{x}{8\sqrt{3}}$

x = $8\sqrt{6}$

x = 19.59

x ≈ 19.6

3 0

2 years ago

Suppose that grade point averages of undergraduate students at one university have a bell-shaped distribution with a mean of 2.5

masya89 [10]

Answer:

$z= \frac{3.44-2.54}{0.45}=2$

$P(X>3.44) = P(Z>2) = 0.025$

Step-by-step explanation:

Previous concepts

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 Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the grade points avergae of a population, and for this case we know the following properties

Where $\mu=2.54$ and $\sigma=0.45$

The empirical rule, also referred to as the three-sigma rule or 68-95-99.7 rule, is a statistical rule which states that for a normal distribution, almost all data falls within three standard deviations (denoted by σ) of the mean (denoted by µ). Broken down, the empirical rule shows that 68% falls within the first standard deviation (µ ± σ), 95% within the first two standard deviations (µ ± 2σ), and 99.7% within the first three standard deviations (µ ± 3σ).

So we can find the z score for the value of X=3.44 in order to see how many deviations above or belowe we are from the mean like this:

$z= \frac{3.44-2.54}{0.45}=2$

So the value of 3.44 is 2 deviations above from the mean, so then we know that the percentage between two deviations from the mean is 95% and on each tail we need to have (100-95)/2 = 2.5% , because the distribution is symmetrical, so based on this we can conclude that:

$P(X>3.44) = P(Z>2) = 0.025$

5 0

3 years ago

Solve the inequality. x – 1 ≤ – 9

Arturiano [62]

Answer:

$X\leq -8$