Answer:
d=3
Step-by-step explanation:
13d=39
d=39/13
d=3
Hello!
6d + 7d = 39 <=>
<=> 13d = 39 <=>
<=> d = 39 : 13 <=>
<=> d = 3 => 6 × 3 + 7 × 3 = 39
Good luck! :)
In an English test, the mean is 60 and the standard deviation is 6. Assuming the scores are normally distributed, answer the following question.
a. what is the percentile rank of the score 65?
b. what is the percentile of the score less than 70?
c. what is percent of the scores is greater than 65?
d. what percent of scores is less than 70?
e. what percent of the score is between 50 and 60?
Answer:
a) A score of 65 is in the 79.67th percentile.
b) A score less than 70 is below the 95.25th percentile.
c) 20.33% of the scores are greater than 65.
d) 95.25% of scores are less than 70.
e) 45.25% of the scores are between 50 and 60.
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
The mean is 60 and the standard deviation is 6.
This means that [tex]\mu = 60, \sigma = 6[/tex]
a. what is the percentile rank of the score 65?
This is the p-value of Z when X = 65.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{65 - 60}{6}[/tex]
[tex]Z = 0.83[/tex]
[tex]Z = 0.83[/tex] has a p-value of 0.7967.
Thus: A score of 65 is in the 79.67th percentile.
b. what is the percentile of the score less than 70?
Below the p-value of Z when X = 70. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{70 - 60}{6}[/tex]
[tex]Z = 1.67[/tex]
[tex]Z = 1.67[/tex] has a p-value of 0.9525.
Thus: A score less than 70 is below the 95.25th percentile.
c. what is percent of the scores is greater than 65?
The proportion is 1 subtracted by the p-value of Z when X = 65.
From item a, when X = 65, Z has a p-value of 0.7967
1 - 0.7967 = 0.2033
0.2033*100% = 20.33%
20.33% of the scores are greater than 65.
d. what percent of scores is less than 70?
The proportion is the p-value of Z when X = 70, which, from item b, is of 0.9525.
0.9525*100% = 95.25%
95.25% of scores are less than 70.
e. what percent of the score is between 50 and 60?
The proportion is the p-value of Z when X = 60 subtracted by the p-value of Z when X = 50.
X = 60
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{60 - 60}{6}[/tex]
[tex]Z = 0[/tex]
[tex]Z = 0[/tex] has a p-value of 0.5.
X = 50
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{50 - 60}{6}[/tex]
[tex]Z = -1.67[/tex]
[tex]Z = -1.67[/tex] has a p-value of 0.0475.
0.5 - 0.0475 = 0.4525
0.4525*100% = 45.25%
45.25% of the scores are between 50 and 60.
Solve for x. Round to the nearest tenth, if necessary.
Can someone help me with this math homework please!
Determine the value of x
2.12 units
2.02 units
12.38 units
0.49 units
Answer:
2.02
Step-by-step explanation:
Hello, I took the quiz. The correct answer is 2.02
Determine if the sequence below is arithmetic or geometric and determine the common difference / ratio in simplest form.
19,10,1,...
[tex]\displaystyle\bf \underbrace{19}_910{\underbrace{1}_9} \Longrightarrow This\: is \:an \:\:arithmetic\:\: progression[/tex]
−3x−8y=−8 y=2−x Is (0,1)(0,1)left parenthesis, 0, comma, 1, right parenthesis a solution of the system?
Answer:
(0,1) is not the solution to the equation
Step-by-step explanation:
Given:
−3x − 8y = −8 (1)
y = 2 − x (2)
Substitute (2) into (1)
−3x − 8y = −8 (1)
- 3x - 8(2 - x) = -8
- 3x - 16 + 8x = -8
- 3x + 8x = -8 + 16
5x = 8
x = 8/5
Substitute x = 8/5 into (2)
y = 2 − x (2)
= 2 - 8/5
= (10-8) / 5
= 2/5
y = 2/5
Solution to the equation:
(x, y) = (8/5, 2/5)
Therefore,
(0,1) is not the solution to the equation
A researcher who examines the causal relationship between amount of exercise (i.e., participants are randomly assigned to 30 minutes of exercise per day or no exercise) and memory abilities is using the ______ research design.
Answer: experimental
Step-by-step explanation:
Experimental research design refers to a research that is conducted with a scientific approach whereby two sets of variables are used. It adheres to the scientific research design.
An experimental research design consist of an hypothesis, a variable which the researcher can manipulate and variables which can be measured. Based on the information given, the experimental research design is used.
If the radius of circle is 50cm then find its area?
Answer:
Area=7850 cm
Step-by-step explanation:
Since the formula for area is A=c(radius squared), we need to plug in the radius first. 50x50=2500. We can identify 'pi' as 3.14 and use that decimal instead of a longer one. The product of 2500 and 3.14 is 7850. Therefore, your answer is 7850 cm
Problem 2. Joe has 7 shirts 4 pairs of pants and 2 pairs of shoes.He needs to make an outfit containing one of each item.How many different outfits are possible?
Answer:
56 different outfits
Step-by-step explanation:
SOMEONE PLEASE HELP ME I'M STUCK
Answer:
57%
Step-by-step explanation:
200+245+125 = 570
570/1000 = .57
Answer:
57%
Step-by-step explanation:
First find the total number of families in the sample.
Total = 350 + 200 + 245 + 125 + 66 + 10 + 4
Total = 1000
Next find the number of families that have 3, 4 or 5 people.
Total(3,4 or 5) = 200 + 245 + 125
Total(3,4 or 5) = 570
Now the % = (Total 3,4 or 5) / Total ) * 100
% = 570 / 1000 * 100
% = 57%
Directions: Given the point and slope, write the equation of the line.
(4, 2); slope = 36
Answer:
y - 2 = 36(x - 4)
Step-by-step explanation:
The equation of a line in point- slope form is
y - b = m(x - a)
where m is the slope and (a, b) a point on the line
Here m = 36 and (a, b ) = (4, 2 ) , then
y - 2 = 36(x - 4) ← equation of line
I NEED HELP WITH 2 QUESTIONSS
1.What is the mean change in the forecasted low temperatures over the next 7 days? Remember, this can be found by averaging the values in the Difference column for the low temperatures. If your answer is not an integer, explain what two integers your answer is between.
LOW TEMPTURES:
WEDNESDAY-79
THURSDAY- 79
FRIDAY- 73
SATURDAY- 73
SUNDAY - 73
MONDAY- 73
TUESDAY- 75
2. What is the mean change in the forecasted high temperatures over the next 7 days? Remember, this can be found by averaging the values in the Difference column for the high temperatures. Show your work and steps. If your answer is not an integer, explain what two integers your answer is between.
WEDNESDAY- 88
THURSDAY- 87
FRIDAY- 90
SATURDAY- 90
SUNDAY- 86
MONDAY- 88
TUESDAY-86
PLEASE ANSWER FAST!!!
what are all the factors 24? please help lol
Answer:
factors are 1,2,3,4,6,8,12,24
According to class 8 please solve
Answer:
i) 4x
ii) Father's age = 3(x + 10)
Son's age = x + 10
iii) 4x + 10 = 3(x + 10)
iv) Present age of the son = x = 20
Present age of the father = 4x = 4(20)
= 80
Step-by-step explanation:
Present age of the son = x
Present age of the father = 4x
Age of the son in 10 years = x + 10
Age of the father in 10 years = 3(x + 10)
4x + 10 = 3(x + 10)
4x + 10 = 3x + 30
4x - 3x = 30 - 10
x = 20
What is X if line a and b are parallel
Answer:
We can determine from their equations whether two lines are parallel by comparing their slopes. If the slopes are the same and the y-intercepts are different, the lines are parallel. If the slopes are different, the lines are not parallel. Unlike parallel lines, perpendicular lines do intersect.
Step-by-step explanation:
Answer:
x = 4
Step-by-step explanation:
8x = 180 - 148 [ corresponding angles are equal ]
8x = 32
x = 4
Its about similar figures and scale drawing
No links
Answer:
5 in
Step-by-step explanation:
by doing a proportion of 2/4 for the known sides, you can find that the smaller triangle has sides that are half of the larger one. so 10/2 equals 5
Answer: X = 5
Step-by-step explanation:
4 divided by 2 = 2
So 10 divided by 2 = 5
What is the domain of the following function ?
Answer:
{-6, 1, 5, 8}
Step-by-step explanation:
The domain is the set of x-coordinates or inputs.
{-6, 1, 5, 8}
What goes in the blanks? The measure of angle θ is 7π/4. The measure of its reference angle is _____°, and tan θ is ______?
Answer:
The measure of angle θ is 7π/4. The measure of its reference angle is 45°, and tan θ is -1.
Answered by GAUTHMATH
What is the next term in the sequence below?
1, 2, 4, 8, 16, . . .
A. 24
B. 32
C. 34
D. 64
B
the number doubles by itself
What is the approximate value of x. Enter only a numeric answer rounded to the nearest tenth
Answer:
14.9 degrees
Step-by-step explanation:
For this problem you can use Tan∅=o/a and solve for the angle:
15.7 / 59 = 0.2661
Then use inverse tangent of 0.2661 to get 14.9.
Juilo spent $64 and now has no money left.He( )had before his purchase
Answer:
64->-?
Step-by-step explanation:
he spent 64 and now he has none so he spent all his money
If a 1 = −3 and a n = −2an − 1, what is the fifth term of the sequence?
Answer:
d
Step-by-step explanation:
o
Step-by-step explanation:
There's on;ly one way I know of that this can be done.You must start at a1 and work your way up to a5
a1 = -3n that's given
a2 =
PLEASE HELP ASAP WHAT IS THE ANSWER TO THIS QUADRATIC EQUATIONNNN
Answer:
pls i don't know
Efectúa las siguientes operaciones, aplicando la propiedad distributiva de la multiplicación. De ser posible simplifique los resultados
e) 3√2 (2√6-√4-5√6-6)
f) -5√2 (√9+√8-3√4-1)
Answer:
Step-by-step explanation:
e) 3√2 (-3√6 -2 -6)
3√2 (-3√6 - 8)
-9√12 - 24√2
-9√(2^2 * 3) - 24√2
-18√3 - 24√2
or
6(-3√3 - 4√2)
f) -5√2 (3 + 2√2 - 6 - 1)
-5√2(-4 + 2√2)
20√2 - 20
or
20(√2 - 1)
Given the net of the rectangular prism, what is its surface area?
Answer:
D. 160
Step-by-step explanation:
Find the average rate of change of g(x)=-2x^3-5 from x=-4 to x=1
Answer:
26
Step-by-step explanation:
We have the average rate of change on the interval [a,b] as
f(b)-f(a)/(b-a)
b = 1 and a = -4
f(b) = f(1) = -2(1)^3 -5 = -2-5 = -7
f(a) = f(-4) = -2(-4)^3 -5 = 128 -5 = 123
so we have;
(123 + 7)/(1+4) = 130/5 = 26
Two times the difference of a number and ten is forty two
Write an equation to represent the sentence:
Answer:
let the number be x
representing the equation...
it will be....
2 times (the number- 10)=42
2 times(x-10)= 42
2(x-10)=42
Replace ∗ with a monomial so that the trinomial may be represented by a square of a binomial: b2 + 20b +*
Given:
The expression is:
[tex]b^2+20b[/tex]
To find:
The a monomial so that the trinomial may be represented by a square of a binomial.
Solution:
If an expression is [tex]x^2+bx[/tex], then be need to add square of half of coefficient of x, i.e., [tex]\left(\dfrac{b}{2}\right)^2[/tex] in the given expression to make in perfect square.
We have,
[tex]b^2+20b[/tex]
Here, coefficient of b is 20,so wee need to add square of half of coefficient of b, i.e., [tex]\left(\dfrac{20}{2}\right)^2[/tex].
[tex]\left(\dfrac{20}{2}\right)^2=10^2[/tex]
[tex]\left(\dfrac{20}{2}\right)^2=100[/tex]
Therefore, we need to add 100 to make [tex]b^2+20b[/tex] a perfect square binomial.
A sheet of plastic has an area of 35 square cm. If the sheet is 5 cm thick, what is the volume?
Answer:
175 cm³
Step-by-step explanation:
Volume = área * thick
Volume = 35cm² * 5cn
Volume = 175 cm³
Answer:
7cm
Step-by-step explanation:
Area = 35cm²
Length= 5cm
Width=?
A=L×B
B=A/L
B=35/5
B=7cm
help help help pls :)
Answer:
[tex]opposite\approx 70.02[/tex]
Step-by-step explanation:
The triangle in the given problem is a right triangle, as the tower forms a right angle with the ground. This means that one can use the right angle trigonometric ratios to solve this problem. The right angle trigonometric ratios are as follows;
[tex]sin(\theta)=\frac{opposite}{hypotenuse}\\\\cos(\theta)=\frac{adjacent}{hypotenuse}\\\\tan(\theta)=\frac{opposite}{adjacent}[/tex]
Please note that the names ([tex]opposite[/tex]) and ([tex]adjacent[/tex]) are subjective and change depending on the angle one uses in the ratio. However the name ([tex]hypotenuse[/tex]) refers to the side opposite the right angle, and thus it doesn't change depending on the reference angle.
In this problem, one is given an angle with the measure of (35) degrees, and the length of the side adjacent to this angle. One is asked to find the length of the side opposite the (35) degree angle. To achieve this, one can use the tangent ([tex]tan[/tex]) ratio.
[tex]tan(\theta)=\frac{opposite}{adjacent}[/tex]
Substitute,
[tex]tan(35)=\frac{opposite}{100}[/tex]
Inverse operations,
[tex]tan(35)=\frac{opposite}{100}[/tex]
[tex]100(tan(35))=opposite[/tex]
Simplify,
[tex]100(tan(35))=opposite[/tex]
[tex]70.02\approx opposite[/tex]