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4 years ago

Assume a random variable x is normally distributed with mean = 90 and standard deviation = 5. Find the indicated probability.

Mathematics

1 answer:

nikklg [1K]4 years ago

7 0

Answer:

16%

Step-by-step explanation:

The indicated probability is actually the area under the standard normal curve to the left of the mean. I used the function normalcdf( on my TI-83 Plus calculator to find this quantity:

normalcdf(-1000,85,90,5) = 0.1587.

Note #1: This quantity (area / probability) is the area to the left of 85.

Note #2: by the Empirical Rule, 68% of data lies within 1 s. d. of the mean, so the area between the mean (90) and the score (85) is half of 68%, or 34%. Subtracting this from 50% (the area to the left of the mean), we get 16%, which is roughly equivalent to the 0.1587 we got earlier.

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Explain why f(x) = x^2+4x+3/x^2-x-2 is not continuous at x = -1.

liberstina [14]

Answer:

The value of x = -1 makes the denominator of the function equal to zero. That is why this value is not included in the domain of f(x)

Step-by-step explanation:

We have the following expression

$f(x) = \frac{x^2+4x+3}{x^2-x-2}$

Since the division between zero is not defined then the function f(x) can not include the values of x that make the denominator of the function zero.

Now we search that values of x make 0 the denominator factoring the polynomial $x^2-x-2$

We need two numbers that when adding them get as a result -1 and when multiplying those numbers, obtain -2 as a result.

These numbers are -2 and 1

Then the factors are:

$(x-2) (x + 1)$

We do the same with the numerator

$x^2+4x+3$

We need two numbers that when adding them get as a result 4 and when multiplying those numbers, obtain 3 as a result.

These numbers are 3 and 1

Then the factors are:

$(x+3)(x + 1)$

Therefore

$f(x) = \frac{(x+3)(x+1)}{(x-2)(x+1)}$

Note that $\frac{(x+1)}{(x+1)}=1$ only if $x \neq -1$

So since $x = -1$ is not included in the domain the function has a discontinuity in $x = -1$

3 0

3 years ago

Please help me ive gotten 2 wrong pelase help me please

Tju [1.3M]

The blue one with four corners!!!

3 0

3 years ago

The function f(x) = 1/3x + 5 and g(x) = x^2 + 4x are shown graphed below. The negative solution to the equation f(x) = g(x) is c

sergij07 [2.7K]

Answer:

Step-by-step explanation:

4 0

3 years ago

Jeremy measured the room to be 10 feet long and 4.5 feet wide. He plans to purchase carpet for the entire room. The carpet cost

Andreyy89

Answer:

$205.73

Step-by-step explanation:

First we find the square area,

multiply 10 by 4.5 and we get 45

we convert feet to meters by dividing it by 3.281

45/3.281=13.71533

we the multiply 13.71533 by 15 to get the total price

we get 205.72996 and round it to 205.72

5 0

3 years ago

Gavin drank 4 5 liter of water Monday before going jogging. He drank 2 3 liter of water after his jog. How much water did Gavin

Hoochie [10]

Answer:

<h2>8.0 liters</h2>

Step-by-step explanation:

The question is not well-formatted, this is supposed to be the correct format

<em>Gavin drank 4.5 liter of water Monday before going jogging. He drank 2.3 liter of water after his jog. How much water did Gavin drink altogether? Write your answer as a mixed number.</em>

Given

we are told that he first drank 4.5 liters of water before jogging

after jogging he drank 2.3 liters

Required

Total amount of water drank

=4.5+3.5

=8.0liters

5 0

3 years ago