How many calculations can this computer preform in one minute?

Which is the graph of a quadratic equation that has a negative discriminant?

Natasha2012 [34]

Answer:

D

Step-by-step explanation:

A negative discriminant indicates that the quadratic equation has no real roots.

Thus the graph does not touch or intersect the x- axis

The only graph that does not touch or intersect the x- axis is the fourth one

5 0

3 years ago

Read 2 more answers

One survey showed that among 785 randomly selected subjects who completed four years of college, 18.3% smoke and a 98% confidenc

Valentin [98]

Answer

a. True

Step-by-step explanation:

Based on this survey we estimate that about $18.3\%$ of the college students smokes. And a $98\%$ confidence interval is $[15.1\% ; 21.6\%]$ . So we know that our estimative for the smoking rate is in the confidence interval with $98\%$ certainty. We also know the estimative for the smoking rate in the general population is $27\%$ . So we can write the two possible hypothesis:

$H_0 =$ Smoking rate is equal to $27\%$ .

$H_1 =$ Smoking rate is not equal to $27\%$ .

We will reject the null hypothesis $(H_0)$ if the estimate doesn't fall into the confidence interval for the college students smoking rate.

Since this condition holds we reject the null hypothesis. So with $98\%$ certainty we say that the smoking rate for the general population is different than the smoking rate for the college students.

6 0

3 years ago

Let x denote the lifetime of a mcchine component with an exponential distribution. The mean time for the component failure is 25

aliina [53]

Answer:

0.1353 = 13.53% probability that the lifetime exceeds the mean time by more than 1 standard deviations

Step-by-step explanation:

Exponential distribution:

The exponential probability distribution, with mean m, is described by the following equation:

$f(x) = \mu e^{-\mu x}$

In which $\mu = \frac{1}{m}$ is the decay parameter.

The probability that x is lower or equal to a is given by:

$P(X \leq x) = \int\limits^a_0 {f(x)} \, dx$

Which has the following solution:

$P(X \leq x) = 1 - e^{-\mu x}$

The probability of finding a value higher than x is:

$P(X > x) = 1 - P(X \leq x) = 1 - (1 - e^{-\mu x}) = e^{-\mu x}$

The mean time for the component failure is 2500 hours.

This means that $m = \frac{2500}, \mu = \frac{1}{2500} = 0.0004$

What is the probability that the lifetime exceeds the mean time by more than 1 standard deviations?

The standard deviation of the exponential distribution is the same as the mean, so this is P(X > 5000).

$P(X > x) = e^{-0.0004*5000} = 0.1353$

0.1353 = 13.53% probability that the lifetime exceeds the mean time by more than 1 standard deviations

4 0

2 years ago

Can a local maximum also be a point of inflection? Explain.

myrzilka [38]

Inflection points are where the function changes concavity. Since concave up corresponds to a positive second derivative and concave down corresponds to a negative second derivative, then when the function changes from concave up to concave down (or vise versa) the second derivative must equal zero at that point. So the second derivative must equal zero to be an inflection point. But don't get excited yet. You have to make sure that the concavity actually changes at that point.

7 0

3 years ago

1.Solve the equation. Check for extraneous solutions.

elena55 [62]

Okay so I did the math.

1. Two solutions were found :
z=-1
z=2/3
Step 1 :Rearrange this Absolute Value Equation

Absolute value equalitiy entered
|2z-3| = 4z-1

Step 2 :Clear the Absolute Value Bars

Clear the absolute-value bars by splitting the equation into its two cases, one for the Positive case and the other for the Negative case.

The Absolute Value term is |2z-3|

For the Negative case we'll use -(2z-3)

For the Positive case we'll use (2z-3)

Step 3 :Solve the Negative Case

      -(2z-3) = 4z-1

     Multiply
      -2z+3 = 4z-1

     Rearrange and Add up
      -6z = -4

     Divide both sides by 6
      -z = -(2/3)

     Multiply both sides by (-1)
      z = (2/3)
     Which is the solution for the Negative Case

Step 4 :Solve the Positive Case

      (2z-3) = 4z-1

     Rearrange and Add up
      -2z = 2

     Divide both sides by 2
      -z = 1

     Multiply both sides by (-1)
      z = -1
     Which is the solution for the Positive Case
Step  5  :Wrap up the solution

z=2/3
 z=-1

2. -6 < x < 26/3

Step 1 :Rearrange this Absolute Value Inequality

Absolute value inequalitiy entered
|3x-4|+5 < 27

Another term is moved / added to the right hand side.

|3x-4| < 22

Step 2 :Clear the Absolute Value Bars

Clear the absolute-value bars by splitting the equation into its two cases, one for the Positive case and the other for the Negative case.

The Absolute Value term is |3x-4|

For the Negative case we'll use -(3x-4)

For the Positive case we'll use (3x-4)

Step 3 :Solve the Negative Case

-(3x-4) < 22

 Multiply
 -3x+4 < 22

 Rearrange and Add up
 -3x < 18

 Divide both sides by 3
 -x < 6

 Multiply both sides by (-1)
 Remember to flip the inequality sign
 x > -6
 Which is the solution for the Negative Case

Step 4 :Solve the Positive Case

(3x-4) < 22

 Rearrange and Add up
 3x < 26

 Divide both sides by 3
 x < (26/3)

 Which is the solution for the Positive Case

Step 5 :Wrap up the solution

-6 < x < 26/3

Solution in Interval Notation

(-6,26/3)

HOPE THIS HELPS :D

7 0

3 years ago