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3 years ago

How many times smaller is 4 × 10-9 than 8 × 10-7? A. 200 B. 20 C. 20,000 D. 2,000

Mathematics

1 answer:

masya89 [10]3 years ago

4 0

Answer:

Step-by-step explanation:

4×10-9= 4

8×10-7=21

21-4=17

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Which of the following is equivalent to (16 3/2)^1/2 ? O 6 O 8 O 12 O 64

Galina-37 [17]

Step-by-step explanation:

$= { ({16}^{ \frac{3}{2} } )}^{ \frac{1}{2} }$

$= { ({( {2}^{4}) }^{ \frac{3}{2} } )}^{ \frac{1}{2} }$

$= {2}^{4 \times \frac{3}{2} \times \frac{1}{2} }$

$= {2}^{ \frac{12}{4} }$

$= {2}^{3}$

$= 2 \times 2 \times 2$

$= 8$

The answer is B.

6 0

2 years ago

On the graph of f(x)=cos x and the interval [0,2π), for what value of x does f(x) achieve a minimum?

Mariulka [41]

Answer:

$cos(\pi)=-1$

Step-by-step explanation:

$f(x)=cos (x)$

State that the values where cos x is minimum:

$x=\pi +2\pi n, n\in \mathbb{Z}$

$cos(0)=1\\$

$cos\left(\frac{\pi}{4} \right)=\frac{\sqrt{2} }{2}$

$cos\left(\frac{\pi}{2} \right)=0$

$cos(\pi)=-1$

$cos\left(\frac{3\pi}{2} \right)=0$

7 0

2 years ago

8.52 The heights of 2-year-old children are normally distributed with a mean of 32 inches and a standard deviation of 1.5 inches

sweet [91]

Answer:

Heights of 29.5 and below could be a problem.

Step-by-step explanation:

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

The heights of 2-year-old children are normally distributed with a mean of 32 inches and a standard deviation of 1.5 inches.

This means that $\mu = 32, \sigma = 1.5$

There may be a problem when a child is in the top or bottom 5% of heights. Determine the heights of 2-year-old children that could be a problem.

Heights at the 5th percentile and below. The 5th percentile is X when Z has a p-value of 0.05, so X when Z = -1.645. Thus

$Z = \frac{X - \mu}{\sigma}$

$-1.645 = \frac{X - 32}{1.5}$

$X - 32 = -1.645*1.5$

$X = 29.5$

Heights of 29.5 and below could be a problem.

4 0

2 years ago

(6+3)+21=6+(3+21) name each property of addition or multiplication

Anna007 [38]

(6 + 3) + 21 = 6 + (3 + 21)

It's an ASSOCIATIVE PROPERTY
(a + b) + c = a + (b + c)

7 0

3 years ago

Find the average of: 15, 8, -22, 24, -9, -18, 16

trasher [3.6K]

The average is 2. To find the average you add all the numbers then divide the sum by the total amount of numbers.

5 0

3 years ago

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