A-( b.(h)126= (4x 1)(x 1)

Which of the following is an example of a quadratic equation?

jasenka [17]

Answer:

C) any eqaution that has a variable or number squared is a qaudratic equation

5 0

3 years ago

What is the common ratio for the geometric sequence below, written as a fraction?

MaRussiya [10]

5/8 hope this helps!!

3 0

3 years ago

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A true-false quiz with 10 questions was given to a statistics class. Following is the probability distribution for the score of

disa [49]

Answer:

$E(X)=\sum_{i=1}^n X_i P(X_i)$

And if we use the values obtained we got:

$E(X)=5*0.05 +6*0.15 +7*0.33 +8*0.28+ 9*0.12 +10*0.07=7.48$

For this case this value means that the expected score is about 7.48

Step-by-step explanation:

For this case we assume the following probability distribution:

X 5 6 7 8 9 10

P(X) 0.05 0.15 0.33 0.28 0.12 0.07

First we need to find the expected value (first moment) and the second moment in order to find the variance and then the standard deviation.

In order to calculate the expected value we can use the following formula:

$E(X)=\sum_{i=1}^n X_i P(X_i)$

And if we use the values obtained we got:

$E(X)=5*0.05 +6*0.15 +7*0.33 +8*0.28+ 9*0.12 +10*0.07=7.48$

For this case this value means that the expected score is about 7.48

In order to find the standard deviation we need to find first the second moment, given by :

$E(X^2)=\sum_{i=1}^n X^2_i P(X_i)$

And using the formula we got:

$E(X^2)=(5^2 *0.05)+(6^2 *0.15)+(7^2 *0.33)+(8^2 *0.28)+ (9^2 *0.12 +(10^2 *0.07))=57.46$

Then we can find the variance with the following formula:

$Var(X)=E(X^2)-[E(X)]^2 =57.46-(7.48)^2 =1.5096$

And then the standard deviation would be given by:

$Sd(X)=\sqrt{Var(X)}=\sqrt{1.5096}=1.229$

5 0

3 years ago

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30, 16, 49, 25 find the median

Ksivusya [100]

Look at the attached picture ⤴

Hope it will help u..

5 0

3 years ago

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Consider the following hypothesis test: H 0: 20 H a: < 20 A sample of 60 provided a sample mean of 19.5. The population stand

viva [34]

Answer:

We reject the null hypothesis and accept the alternate hypothesis. Thus, it be concluded that the population mean is less than 20.

Step-by-step explanation:

We are given the following in the question:

Population mean, μ = 60

Sample mean, $\bar{x}$ = 19.5

Sample size, n = 60

Alpha, α = 0.05

Population standard deviation, σ = 1.8

First, we design the null and the alternate hypothesis

$H_{0}: \mu = 20\\H_A: \mu < 20$

We use One-tailed z test to perform this hypothesis.

Formula:

$z_{stat} = \displaystyle\frac{\bar{x} - \mu}{\frac{\sigma}{\sqrt{n}} }$

Putting all the values, we have

$z_{stat} = \displaystyle\frac{19.5 - 20}{\frac{1.8}{\sqrt{60}} } = -2.151$

Now, $z_{critical} \text{ at 0.05 level of significance } = -1.64$

Since,

$z_{stat} < z_{critical}$

We reject the null hypothesis and accept the alternate hypothesis. Thus, it be concluded that the population mean is less than 20.

5 0

3 years ago