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2 years ago

Which is equivalent to x3y-7

Mathematics

2 answers:

Simora [160]2 years ago

9 0

Answer:

$\dfrac{x^3}{y^7}$

Step-by-step explanation:

Rule of exponents:

$a^{-n} = \dfrac{1}{a^n}$

$x^3y^{-7} = x^3 \times \dfrac{1}{y^7} = \dfrac{x^3}{y^7}$

Natalka [10]2 years ago

6 0

Answer:

x³/ y^7

Step-by-step explanation:

You might be interested in

According to the WHO MONICA Project the mean blood pressure for people in China is 128 mmHg with a standard deviation of 23 mmHg

Sati [7]

Answer:

a) Mean blood pressure for people in China.

b) 38.21% probability that a person in China has blood pressure of 135 mmHg or more.

c) 71.30% probability that a person in China has blood pressure of 141 mmHg or less.

d) 8.51% probability that a person in China has blood pressure between 120 and 125 mmHg.

e) Since Z when X = 135 is less than two standard deviations from the mean, it is not unusual for a person in China to have a blood pressure of 135 mmHg

f) 157.44mmHg

Step-by-step explanation:

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.

If X is two standard deviations from the mean or more, it is considered unusual.

In this question:

$\mu = 128, \sigma = 23$

a.) State the random variable.

Mean blood pressure for people in China.

b.) Find the probability that a person in China has blood pressure of 135 mmHg or more.

This is 1 subtracted by the pvalue of Z when X = 135.

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

$Z = \frac{135 - 128}{23}$

$Z = 0.3$

$Z = 0.3$ has a pvalue of 0.6179

1 - 0.6179 = 0.3821

38.21% probability that a person in China has blood pressure of 135 mmHg or more.

c.) Find the probability that a person in China has blood pressure of 141 mmHg or less.

This is the pvalue of Z when X = 141.

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

$Z = \frac{141 - 128}{23}$

$Z = 0.565$

$Z = 0.565$ has a pvalue of 0.7140

71.30% probability that a person in China has blood pressure of 141 mmHg or less.

d.)Find the probability that a person in China has blood pressure between 120 and 125 mmHg.

This is the pvalue of Z when X = 125 subtracted by the pvalue of Z when X = 120. So

X = 125

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

$Z = \frac{125 - 128}{23}$

$Z = -0.13$

$Z = -0.13$ has a pvalue of 0.4483

X = 120

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

$Z = \frac{120 - 128}{23}$

$Z = -0.35$

$Z = -0.35$ has a pvalue of 0.3632

0.4483 - 0.3632 = 0.0851

8.51% probability that a person in China has blood pressure between 120 and 125 mmHg.

e.) Is it unusual for a person in China to have a blood pressure of 135 mmHg? Why or why not?

From b), when X = 135, Z = 0.3

Since Z when X = 135 is less than two standard deviations from the mean, it is not unusual for a person in China to have a blood pressure of 135 mmHg.

f.) What blood pressure do 90% of all people in China have less than?

This is the 90th percentile, which is X when Z has a pvalue of 0.28. So X when Z = 1.28. Then

X = 120

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

$1.28 = \frac{X - 128}{23}$

$X - 128 = 1.28*23$

$X = 157.44$

157.44mmHg

6 0

1 year ago

The cylinder below has r = 10 inches and a volume of 6283 cubic inches to the nearest cubic inch. Find the height of the cylinde

kaheart [24]

V=hpir^2
r=10
v=6283

6283=hpi10^2
6283=100hpi
divide both sides by 100
62.83=hpi
aprox pi=3.141592
divide both sides by pi
19.9994143=h
so about 20 inches

6 0

1 year ago

Caroline needs to find 15% of $128, but she doesn't have a calculator. Thoroughly explain how she can do this mentally, detailin

IrinaK [193]

Answer:

The correct answer is $19.2.

Step-by-step explanation:

Caroline needs to find 15% of $128, but she doesn't have a calculator.

Caroline should start by finding the value of 10 % of any number as it is given by dividing the number by 10. Therefore 10% of $128 is given by $\frac{128}{10}$ = $12.8.

Now she can find the value of 5% of $128 which is given by dividing the 10% value of any number by 2. Thus 5% of $128 = $\frac{12.8}{2}$ = $6.4

Thus to calculate the value of 15% of $128 is given by adding 10% of 128 and 5% of 128 = $ (12.8 + 6.4) = $ 19.2.

Thus the value of 15% of $128 is $19.2.

5 0

2 years ago

A car that retails for $14,999 has a sticker on the windshield that says, "$429/mo for 48 months." What interest rate is this ca

kkurt [141]

14,999(1+.o825)^4= 20,595. $429x48 months= 20,592
Interest rate 8 1/4%

Check 20592/14999= 1.37289
Log(1.37289)/ log(1.0825)= 3.99 years

4 0

1 year ago

Read 2 more answers

Nick billups is paid a salary of $ 900 a month, a 2 % commission on all sales, and 1.8 % more on monthly sales over $ 17,500. In

Trava [24]

June :
900 + 0.02(48,500) + 0.018(48500 - 17500) =
900 + 970 + 558 = 2428 <==

July :
900 + .02(50,200) + 0.018(50200 - 17500) =
900 + 1004 + 588.60 = 2492.60 <===

5 0

1 year ago

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