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A major credit card company has determined that customers charge between $100 and $1100 per month. If the monthly amount charged

Alexxx [7]

Answer:

a) $E(X) = \frac{a+b}{2} = \frac{100+1100}{2}=600$

b) First we need to calculate the variance given by this formula:

$Var(X) = \frac{(b-a)^2}{12}= \frac{(1100-100)^2}{12} = 83333.33$

And the deviation would be:

$Sd(X) = \sqrt{83333.33}= 288.675$

c) $P(600 < X< 889) = P(X$

And using the cdf we got:

$P(600 < X< 889)= F(889) -F(600) = \frac{889-100}{1000} -\frac{600-100}{1000}= 0.789- 0.5= 0.289$

d) $P(311 < X< 889)= F(889) -F(311) = \frac{889-100}{1000} -\frac{311-100}{1000}= 0.789- 0.211= 0.578$

Step-by-step explanation:

For this case we define the random variable X who represent the customers charge, and the distribution for X on this case is:

$X \sim Unif (a= 100, b=1100)$

Part a

For this case the average is given by the expected value and we can use the following formula:

$E(X) = \frac{a+b}{2} = \frac{100+1100}{2}=600$

Part b

First we need to calculate the variance given by this formula:

$Var(X) = \frac{(b-a)^2}{12}= \frac{(1100-100)^2}{12} = 83333.33$

And the deviation would be:

$Sd(X) = \sqrt{83333.33}= 288.675$

Part c

For this case we want to find the percent between 600 and 889, so we can use the cumulative distribution function given by:

$F(x) = \frac{X -100}{1100-100}= \frac{x-100}{1000}, 100 \leq X \leq 1100$

And we can find this probability:

$P(600 < X< 889) = P(X$

And using the cdf we got:

$P(600 < X< 889)= F(889) -F(600) = \frac{889-100}{1000} -\frac{600-100}{1000}= 0.789- 0.5= 0.289$

Part d

$P(311 < X< 889) = P(X$

And using the cdf we got:

$P(311 < X< 889)= F(889) -F(311) = \frac{889-100}{1000} -\frac{311-100}{1000}= 0.789- 0.211= 0.578$

6 0

3 years ago

The probability that it will snow on the last day of January is 85%. If the probability remains the same of the first eight day

MrRa [10]

Answer:

Here, we have:

P(5 days snow in this 8 days) = 8C5 x (0.85)^5 x (1 - 0.85)^3 = 0.084

P(6 days snow in this 8 days) = 8C6 x (0.85)^6 x (1 - 0.85)^2 = 0.238

P(7 days snow in this 8 days) = 8C7 x (0.85)^7 x (1 - 0.85)^1 = 0.385

P(8 days snow in this 8 days) = 8C8 x (0.85)^8 x (1 - 0.85)^0 = 0.272

Add up those above, then the probability that it will snow AT LEAST five of those days in February:

P = 0.084+ 0.238 + 0. 385 + 0.272 = 0.979

Hope this helps!

:)

5 0

4 years ago

How many sides are there on a convex polygon if the sum of the interior angles is 3240?

svp [43]

Answer:

20

Step-by-step explanation:

Let the number of sides be n

One exterior angle = 360/n

Exterior angle + interior angle = 180

Interior angle = 180 - Exterior angle

= 180 - 360/n

Sum of interior angle = n(180 - 360/n) = 3240

n(180 - 360/n) = 3240

180n - 360 = 3240

180n = 3240 - 360

= 3600

n = 3600/180

= 20

8 0

3 years ago

Juan picked 67 oranges. He wants to

Aleks04 [339]

Answer:

9 full pitchers 4 will not be used

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

This is the question

Sonja [21]

Answer:

The first option: As the x-values go to positive infinity, the function's values go to negative infinity.

Step-by-step explanation:

Let's focus on the right part of the graph. Notice that at x = 1, the line is on the negative y-axis. The same thing happens to when we locate x = 2, it still continues to go down approaching negative infinity.

5 0

3 years ago