1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
STatiana [176]
2 years ago
14

You buy five books that are equal in

Mathematics
2 answers:
max2010maxim [7]2 years ago
5 0
5x + 8 = 26.50 ; x represents the price of 1 book
Georgia [21]2 years ago
4 0

Answer:

5x+8=26.50

Step-by-step explanation:

Because the books are equal in price, we can use x to represent the price of the books and 5 to represent the amount, so it would be written as 5x. Then we add 8 because that's the price of the one DVD. It tells the total is 26.50, so the full equation written would be <u>5x+8=26.50</u>

You might be interested in
Find the equation of a line that contains the points (6,3) and (6,−2).
RSB [31]

Answer:

x  = 6

Step-by-step explanation:

First find the gradient,

Gradient = \frac{y2-y1}{x2-x1} = \frac{-2-3}{6-6} =\frac{-5}{0} =0

Since this line has no gradient, it means that it's a horizontal or vertical line. We cannot substitute in the values because the gradient is 0 so this line will only be x = 6

3 0
3 years ago
Read 2 more answers
Would you rather have
umka2103 [35]

Answer:

Two cubes of gold one is 24 m per side

Step-by-step explanation:

6 0
3 years ago
Read 2 more answers
A researcher used a sample of n = 60 individuals to determine whether there are any preferences among six brands of pizza. Each
Blizzard [7]

Answer:

1) χ² ≥ 11.07

2) Goodness of fit test, df: χ²_{3}

Independence test, df: χ²_{1}

The goodness of fit test has more degrees of freedom than the independence test.

3) e_{females.} = 80

4) H₀: P_{ij}= P_{i.} * P_{.j} ∀ i= 1, 2, ..., r and j= 1, 2, ..., c

5) χ²_{6}

Step-by-step explanation:

Hello!

1)

The researcher took a sample of n=60 people and made them taste proof samples of six different brands of pizza and choose their favorite brand, their choose was recorded. So the study variable is the following:

X: favorite pizza brand, categorized in brand 1, brand 2, brand 3, brand 4, brand 5 and brand 6.

The Chi-square goodness of fit test is done with the following statistic:

χ²= ∑\frac{(O_i-E_i)^2}{E_i} ≈χ²_{k-1}

Where k represents the number of categories of the study variable. In this example k= 6.

Remember, the rejection region for the Chi-square tests of "goodnedd of fit", "independence", and "homogeneity" is allways one-tailed to the right. So you will only have one critical value.

χ²_{k-1; 1 - \alpha }

χ²_{6-1; 1 - 0.05 }

χ²_{5; 0.95 } = 11.070

This means thar the rejection region is χ² ≥ 11.07

If the Chi-Square statistic is equal or greather than 11.07, then you reject the null hypothesis.

2)

The statistic for the goodness of fit is:

χ²= ∑\frac{(O_i-E_i)^2}{E_i} ≈χ²_{k-1}

Degrees of freedom: χ²_{k-1}

In the example: k= 4 (the variable has 4 categories)

χ²_{4-1} = χ²_{3}

The statistic for the independence test is:

χ²= ∑∑\frac{(O_ij-E_ij)^2}{E_ij} ≈χ²_{(r-1)(c-1)} ∀ i= 1, 2, ..., r & j= 1, 2, ..., c

If the information is in a contingency table

r= represents the total of rows

c= represents the total of columns

In the example: c= 2 and r= 2

Degrees of freedom: χ²_{(r-1)(c-1)}

χ²_{(2-1)(2-1)} = χ²_{1}

The goodness of fit test has more degrees of freedom than the independence test.

3)

To calculate the expected frecuencies for the independence test you have to use the following formula.

e_{ij} = n * P_i. * P_.j = n * \frac{o_i.}{n} * \frac{o_.j}{n}

Where o_i. represents the total observations of the i-row, o_.j represents the total of observations of the j-column and n is the sample size.

Now, this is for the expected frequencies in the body of the contingency table, this means the observed and expected frequencies for each crossing of categories is not the same.

On the other hand, you would have the totals of each category and population in the margins of the table (subtotals), this is the same when looking at the observed frequencies and the expected frequencies. Wich means that the expected frequency for the total of a population is the same as the observed frequency of said population. A quick method to check if your calculations of the expected frequencies for one category/population are correct is to add them, if the sum results in the subtotal of that category/population, it means that you have calculated the expected frequencies correctly.

The expected frequency for the total of females is 80

Using the formula:

(If the females are in a row) e_{females.} = 100 * \frac{80}{100} * \frac{0}{100}

e_{females.} = 80

4)

There are two ways of writing down a null hypothesis for the independence test:

Way 1: using colloquial language

H₀: The variables X and Y are independent

Way 2: Symbolically

H₀: P_{ij}= P_{i.} * P_{.j} ∀ i= 1, 2, ..., r and j= 1, 2, ..., c

This type of hypothesis follows from the definition of independent events, where if we have events A and B independent of each other, the probability of A and B is equal to the product of the probability of A and the probability of B, symbolically: P(A∩B) = P(A) * P(B)

5)

In this example, you have an independence test for two variables.

Variable 1, has 3 categories

Variable 2, has 4 categories

To follow the notation, let's say that variable 1 is in the rows and variable 2 is in the columns of the contingency table.

The statistic for this test is:

χ²= ∑∑\frac{(O_ij-E_ij)^2}{E_ij} ≈χ²_{(r-1)(c-1)} ∀ i= 1, 2, ..., r & j= 1, 2, ..., c

In the example: c= 3 and r= 4

Degrees of freedom: χ²_{(r-1)(c-1)}

χ²_{(3-1)(4-1)} = χ²_{6}

I hope you have a SUPER day!

4 0
3 years ago
I need help thank you
avanturin [10]

Answer:

The area is 252

Step-by-step explanation:

6 0
2 years ago
Read 2 more answers
Heyy! i’ll give brainliest please help
pantera1 [17]
It is persia brainliest please
4 0
2 years ago
Other questions:
  • When you roll two six-sides dice, you get the following 11 combined outcomes: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12. What are th
    10·1 answer
  • Sam is shopping for a new pairs of shoes. On Monday the shoes were on sale for %40.00, but because they became popular, by Satur
    7·2 answers
  • Use the product, quotient, and power rules of logarithms to rewrite the expression as a single logarithm. Assume that all variab
    5·1 answer
  • What is the answer to 5(10^x+2)=0.25
    15·1 answer
  • Please help thanks very much
    8·1 answer
  • I’m not sure what the last answer is. Please help!
    10·2 answers
  • ....................
    11·2 answers
  • Given the circle below find the value of arc AB.<br> (13x + 2)<br> A<br> B.<br> 48<br> D
    7·1 answer
  • BRAINLIST IF CORRECT WORTH 100POINTS
    6·2 answers
  • The graph below shows the same shape was pushing the blue graph
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!