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3 years ago

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Suppose a brand of lightbulbs is normally distributed with a mean life of 1900 hours and a standard deviation of 50 hours. Find

the probability that a lightbulb will last between 1825 hours and 1980 hours

1 answer:

Alexxandr [17]3 years ago

6 0

I am not sure exactly how to do it but based on my knowledge, I think the answer would be 1/38

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Open notes test: Relations, Functions and Slope

Karolina [17]

Answer:

I'm not sure what your asking

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2 years ago

Third-degree, with zeros of −3 , − 2 , and 1 , and passes through the point ( 3 , 11 ) .

Masja [62]

Answer:

y = ( x + 3 ) * ( x + 2 ) * ( x - 1 )* 11/60

Step-by-step explanation:

Lets y = f(x) in a cartesian coordinates

Having three zeros:

x = -3 ⇒ x = -2 ⇒ and x = 1

That meas that if x takes the above mentioned values " y " must be zero

therefore y must be of the form

f (x) = y = ( x + 3 ) * ( x + 2 ) * ( x - 1 ) (1)

In that case for y to be zero one of the factors should be zero or

y = 0 x + 3 = 0 and x = - 3 is a zero of the function y .

The same reasoning applies for the other two roots

Now we have to evaluate the other condition.

According to problem statement the function passes through the point ( 3, 11 ) , that means that when x = 3 , y have to be 11, therefore we plug in equation (1) that value to see what happens

y = ( x + 3 ) * ( x + 2 ) * ( x - 1 )

11 = ( 3 + 3 ) * ( 3 + 2 ) + ( 3 - 1) = 6*5*2 = 60

Then we adjust the expression (1) to meet the condition of the function passing through point ( 3 , 11) as:

y = ( 3 + 3 ) * ( 3 + 2 ) + ( 3 - 1) * 11/60 (2)

and check to see if we did right

for y to be zero x can be x = - 3 x = -2 and x = 1 in all these cases y = 0. And if x = 3 in equation (2) y = 11. And that what we want to shown. Then the solution is:

y = ( x + 3 ) * ( x + 2 ) * ( x - 1 )* 11/60

8 0

3 years ago

At the beginning of the season, a sports writer predicts the teams that will finish in the top three places in the eastern, cent

serious [3.7K]

Answer: B. Ordinal

Step-by-step explanation:

Given statement : A sports writer predicts the teams that will finish in the top three places in the eastern, central, and western divisions. It means he will predicts the teams that will finish in an order ( from first to third ) . It means the sports writer likely to use ordinal scale.

Hence, B is the right answer.

An ordinal scale is a level of measurement scale which is used to arrange a data into an order.

4 0

3 years ago

What is the midpoint of the segment show below?

USPshnik [31]

Answer:

The answer would be c) (5,1/2)!

Hope this helps!

Brainliest?

7 0

3 years ago

Regal theater in Tikahtnu sold 548 tickets to Moana on Sunday. A adult’s ticket was $6.50 while a child’s ticket was $3.50. In t

irga5000 [103]

Regal theater sold 321 adult tickets and 227 children tickets.

Step-by-step explanation:

Given,

Cost of each adult ticket = $6.50

Cost of each child's ticket = $3.50

Total tickets sold = 548

Total worth of sold tickets = $2881

Let,

x represent the number of adult tickets sold

y represent the number of child tickets sold

According to given statement;

x+y=548 Eqn 1

6.50x+3.50y=2881 Eqn 2

Multiplying Eqn 1 by 6.50

$6.50(x+y=548)\\6.50x+6.50y=3562\ \ \ Eqn\ 3$

Subtracting Eqn 2 from Eqn 3

$(6.50x+6.50y)-(6.50x-3.50y)=3562-2881\\6.50x+6.50y-6.50x-3.50y=681\\3y=681$

Dividing both sides by 3

$\frac{3y}{3}=\frac{681}{3}\\y=227$

Putting y=227 in Eqn 1

$x+227=548\\x=548-227\\x=321$

Regal theater sold 321 adult tickets and 227 children tickets.

Keywords: linear equation, elimination method

Learn more about elimination method at:

#LearnwithBrainly

6 0

3 years ago