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3 years ago

Which number is rational, an integer, and a real number?

Mathematics

1 answer:

NikAS [45]3 years ago

7 0

The answer is C.

-5 is an integer because integers are all whole numbers with the inclusion of their opposites (negative values).
-5 is rational because it can be expressed as a ratio of two integers (-5/1).
-5 is a real number because all integers and rational numbers are real numbers.

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Under normal conditions, 1.5 feet of snow will melt into 2 inches of water. During a winter season high in the mountains, 49 fee

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Answer:

Step-by-step explanation:

65.333332

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2 years ago

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Identify the initial amount a and the growth factor b in the exponential function. f(x) = 620 • 7.8x

jenyasd209 [6]

Answer:

Initial amount (a)= 620

Growth factor (b)= 7.8

Step-by-step explanation:

620 is the initial amount and is multiplied by 7.8 x which is the growth factor.

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3 years ago

A customer would like a wall constructed that is 4 feet high. If the bricklayer wants to use all of the 1,820 bricks that he has

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Answer: 7,280

Step-by-step explanation:

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3 years ago

In a call center that stays open all the time, calls arrive as a poisson process with a mean rate of 0.3 complaints per hour.(a)

DENIUS [597]

The probability the 51st call arriaves within 150hours is 0.0431, the probability the next call arrives within the next 2 hours 0.5488, the probability the sum of these 50 numbers is less than 356 is 0.4165.

Data;

Mean rate = 0.3
x = 50
standard deviation = ?

<h3>Poission Rule</h3>

Using poission formula,

$P(x=x) = \frac{e^-^\lambda - \lambda^x}{x!}\\\lambda = 0.3 per minute$

Let's substitute the values into the formula.

For 50 calls in 150 hours

For 150 hours = x = 0.3 * 150 = 45

$p(x=50) = \frac{e^-^4^5 * 45^5^0}{50!} = 0.0431$

The probability the next call arrives after 2 hours.

$\lambda = 0.3 * 2 = 0.6\\p(x=0) = \frac{e^-^0^.^6 * 0.6^0}{0!} = 0.5488$

The number of calls recieved each day is recorded for 50 consecutive days.

for 50 days;

$\lambda = 0.3 * 50 * 24 = 360$

The mean = 360

The standard deviation is given as

$S.D = \sigma =\sqrt{360} = 18.974\\$

The probability the sum of these 50 number is less than 356 is

$p = (x < 356) = z = \frac{356 - 360}{18.974} = -0.2108\\p(z < -0.2108) = 0.4165$

Learn more on poission formula here;

brainly.com/question/7879375

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2 years ago

A study of 420,076 cell phone users found that 131 of them developed cancer of the brain or nervous system. Prior to this study

Keith_Richards [23]

Answer:

a) 95% Confidence interval = (0.026%, 0.037%) to 3 d.p

b) The result of the 95% confidence interval does not agree with the previous rate of such cancer because the value 0.0224% does not lie within this confidence interval obtained.

Step-by-step explanation:

Confidence Interval for the population proportion is basically an interval of range of values where the true population proportion can be found with a certain level of confidence.

Mathematically,

Confidence Interval = (Sample proportion) ± (Margin of error)

Sample proportion = (131/420076) = 0.0003118483 = 0.0312%

Margin of Error is the width of the confidence interval about the mean.

It is given mathematically as,

Margin of Error = (Critical value) × (standard Error)

Critical value at 95% confidence interval for sample size of 420,076 is obtained from the z-tables because the sample size is large enough for the properties of the sample to approximate the population properties.

Critical value = 1.960 (from the z-tables)

Standard error = σₓ = √[p(1-p)/n]

n = sample size = 420,076

σₓ = √(0.0003118×0.999688/420076) = 0.0000272421 = 0.0000272

95% Confidence Interval = (Sample proportion) ± [(Critical value) × (standard Error)]

CI = 0.000312 ± (1.96 × 0.0000272)

CI = 0.000312 ± 0.0000534

95% CI = (0.0002586055, 0.0003653945)

95% Confidence interval = (0.000259, 0.000365)

95% Confidence interval = (0.0259%, 0.0365%) = (0.026%, 0.037%) to 3 d.p

b) The result of the 95% confidence interval does not agree with the previous rate of such cancer because the value 0.0224% does not lie within this confidence interval obtained.

Hope this Helps!!!

7 0

3 years ago