Which two ratios form a proportion? A) 4 20 and 1 5 B) 4 20 and 2 5 C) 20 4 and 1 5 D) 20 4 and 2 5

Troy says that 0.9>0.90 because tenths are greater than hundredths.Keith says that 0.9<0.90 bra side 90 is greater than 9.

stellarik [79]

Answer:

Neither Troy nor Keith is correct.

Step-by-step explanation:

Neither Troy nor Keith is correct.

The value 0.9 is the same as the value 0.90.

The zeros after a decimal point are always insignificant unless they are followed by a number different from zero.

0.90 = 0.900 = 0.9000 = 0.90000 = ... = 0.9000000000

and all these can be easily written as 0.9, as the zeros after the decimal point do not change the value.

But 0.901, 0.9000004, 0.90002, and so on are all different, and the zeros are relevant, as they are followed by numbers different from zero.

5 0

3 years ago

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Jon worked x hours at the car wash on Friday and the same number of hours on Saturday. His total pay for Friday and Saturday was

slamgirl [31]

Answer:

$175 \div 48 = 3.65$

Step-by-step explanation:

so they get paid 175 in total for two days so 24 hours are in one day but we are looking for the hourly pay for two days so we use 48 as a dividing variable . so 175 divide by 48 is 3.65 so they get paid 3.65 per hour but if we have to round it out then 4 per hour

6 0

3 years ago

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The demand for a daily newspaper at a newsstand at a busy intersection is known to be normally distributed with a mean of 150 an

AURORKA [14]

Answer:

171 newspapers.

Step-by-step explanation:

Problems of normally distributed samples are solved using 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.

In this problem, we have that:

$\mu = 150, \sigma = 25$

How many newspapers should the newsstand operator order to ensure that he runs short on no more than 20% of days

The number of newspapers must be on the 100-20 = 80th percentile. So this value if X when Z has a pvalue of 0.8. So X when Z = 0.84.

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

$0.84 = \frac{X - 150}{25}$

$X - 150 = 0.84*25$

$X = 171$

So 171 newspapers.

4 0

3 years ago

Let f(x)=x2−2x−4 . What is the average rate of change for the quadratic function from x=−1 to x = 4?

goblinko [34]

Answer:

The average rate of change for f(x) from x=−1 to x = 4 is, 1

Step-by-step explanation:

Average rate A(x) of change for a function f(x) over [a, b] is given by:

$A(x) = \frac{f(b)-f(a)}{b-a}$

As per the statement:

$f(x) = x^2-2x-4$

we have to find the average rate of change from x = -1 to x = 4

At x = -1

$f(-1) = (-1)^2-2(-1)-4 = 1+2-4 = -1$

and

at x = 4

$f(4) = (4)^2-2(4)-4 = 16-8-4 = 4$

Substitute these in [1] we have;

$A(x) = \frac{f(4)-f(-1)}{4-(-1)}$

⇒ $A(x) = \frac{4-(-1)}{4+1}$

⇒ $A(x) = \frac{5}{5}$

Simplify:

A(x) = 1

Therefore, the average rate of change for f(x) from x=−1 to x = 4 is, 1

4 0

3 years ago

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48. Reading Rates The reading speed of sixth-grade students is approximately normal, with a mean speed of 125 words per minute a

son4ous [18]

Answer:

The reading speed of a sixth-grader whose reading speed is at the 90th percentile is 155.72 words per minute.

Step-by-step explanation:

Problems of normally distributed samples are solved using 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.

In this problem, we have that:

$\mu = 125, \sigma = 24$