There is a probability of 77% that the mean of this sample is between 19.25 hours and 21.0 hours
Z score is used to determine by how many standard deviations the raw score is above or below the mean. The z score is given by:
[tex]z=\frac{x-\mu}{\sigma/\sqrt{n} } \\\\where\ x=raw\ score,\mu=mean,\sigma=standard\ deviation,n=sample\ size[/tex]
Given that μ = 20, σ = 7, n = 125.
For x = 19.25:
[tex]z=\frac{19.25-20}{7/\sqrt{125} } =-1.20\\\\\\For\ x=21:\\\\z=\frac{21-20}{7/\sqrt{125} } =0.62[/tex]
From the normal distribution table, P(-1.20 < z < 0.62) = P(z < 0.62) - P(z < -1.2) = 0.8849 - 0.1151 = 0.7698 = 77%
There is a probability of 77% that the mean of this sample is between 19.25 hours and 21.0 hours
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The width of a rectangle is represented by 5 1 2y.
The length is twice as long as the width. What is the
perimeter of the rectangle?
Answer:
33y
Step-by-step explanation:
since the equation of perimeter for a rectangle is lengthX2 + widthX2
and the width is given to be 5 1/2y is it? If it is so then the length will be 11y since 2X5 1/2y is 11y
and the perimeter will then be calculated as so;
11yX2 + 5 1/2yX2
so it will be 22y+11y which will give you 33y
The mass of a an atom of helium is 6.65 x 10−24. Use scientific notation to express the mass of 250 helium atoms. A) 1.6625 x 10−21 B) 1.6625 x 10−22 C) 1.6625 x 10−24 D) 1.6625 x 10−26
Answer: its A
Step-by-step explanation:
i know this is it
Chris wants to order DVDS over the internet. Each DVD costs $12.99 and shipping order costs $9.99. If he can spend no more than $100 how many DVDs can he buy?
Answer:
4
Step-by-step explanation:
I think its 4 because the max DVD's he could have bought if shipping was free was 7 but since shipping is not free,he has to equal the amount so 12.99+9.99= 22.98 and the maximum multiplication by 22.98 with the maximum number as 100 would be 91.92, thats my answer
Can someone help me please
Answer:
31.25
Step-by-step explanation:
Divide 250 by 8=31.25
Evaluate (4x + 4)(7x - 3).
Answer:
28x^2+16x-12
Step-by-step explanation:
(4x+4)(7x-3)
28x^2+28x-12x-12
28x^2+16x-12
4. Tomas uses 12 gallons of water to prepare lemonade for a party. The lemonade recipe states that for every 2 quarts of water, he should add cup of lemon juice and cup 1 of sugar. How much lemon juice does Tomas need?
Answer:
Thomas will need 24 cups of lemon juice.
Step-by-step explanation:
There are 4 quarts in every gallon.
12 x 4 = 48
2 cups of lemon juice for every 2 quarts of water.
48 / 2 = 24
Hope This Helps!
First to answer correctly will get brainiest.
How to get a number 100 by using four sevens (7’s) and a one (1)?
Answer:
read step-by-step explanation
Step-by-step explanation:
it's a trick question u can't u can get close doing (7+7)×(7+1)-7=105 but it's not 100
22 loaves of bread have 506 slices of bread how many slices of bread do 6 loaves have
Answer:
138 slices
Step-by-step explanation:
506 / 22 = 23 slices per loaf
23 x 6 = 138 slices
It takes 82 pounds of seed to completely plant 11 acre field. How many ponds of seed are needed per acre?
Answer:
7.5lbs
Step-by-step explanation:
82/11 = 7.45454545lbs
Rounded to 7.4lbs
Hope that helps
Answer:
7 5/11
Step-by-step explanation:
you divide 82 and 11 and you get 7.45454545
Pls look at the picture for question.
Answer:
-5, -2, 3, 4
They are in the correct order already :)
Step-by-step explanation:
They greater a negative number is the less it becomes and positive numbers are always greater than negative ones.
Good luck :)
What is the discriminate of the following quadratic equation?
4x^2 - 2x + 6 = 0
-92
Step-by-step explanation:
If a quadratic equation has the following form:
[tex]ax^2 + bx + c =0, \;\;\;a \neq 0[/tex]
then its discriminant D is defined as
[tex]D = b^2 - 4ac[/tex]
In our given quadratic equation, a = 4, b = -2 and c = 6, so its discriminant is
[tex]D = (-2)^2 - 4(4)(6) = -92[/tex]
Note: The value of the discriminant D will determine the characteristics of the roots of the quadratic equation according to the following rules:
[tex]D > 0,\;\;[/tex] there will be 2 real roots
[tex]D = 0,\;\;[/tex] there will be 1 real root
[tex]D < 0,\;\;[/tex] there will be 2 imaginary roots
Hence our given quadratic equation will not have any real roots but only imaginary ones.
Identify the slope and y-intercept of the line 4x + 2y < 3.
Answer:
Step-by-step explanation:
4x+2y<3
y<-2x + [tex]\frac{3}{2}[/tex]
A chef prepared 100 plates of shrimp. There were 8 shrimp on each plate. How many shrimp did the chef prepare?
Answer:
800 shrimp
Step-by-step explanation:
100 plates of shrimp
8 shrimp on each plate
100 × 8 = 800
= 800 shrimp were prepared by the chef
Hope this helps.
Plz help if understand this problem
This is the same as typing in 0.5x^7
Other equivalent forms are (1/2)x^7 or (x^7)/2
=====================================================
Work Shown:
[tex]\frac{d}{dx}\left[f(x^2)\right] = x^8\\\\f'(x^2)*\frac{d}{dx}(x^2) = x^8\\\\f'(x^2)*2x = x^8\\\\f'(x^2) = \frac{x^8}{2x}\\\\f'(x^2) = \frac{x^7}{2}\\\\f'(x^2) = \frac{1}{2}x^7\\\\f'(x^2) = \boldsymbol{0.5x^7}\\\\[/tex]
I used the chain rule on the second step. The chain rule will apply the derivative to the outer function f(x^2). Then we also apply the derivative to the inner function x^2 to get 2x, which is multiplied with f ' (x^2). From that point, we isolate f ' (x^2).
Side note: When applying the first derivative, it might help to think of f(x^2) as simply f(x) on a temporary basis.
How do you divide 35 and 97.3
Answer:
To divide a decimal number by a decimal number, multiply the divisor by as many tens as necessary until we get a whole number, and remember to multiply the dividend by the same number of tens. For example, 13.8 ÷ 0.6 becomes 138 ÷ 6 = 23.
For each computer Isabella sells, she earns a 5% commission. If she sells 3 computers for
$985.00 each, what is her commission?
$14.78
b. $49.25
$147.75
a.
C.
There are 28 girls and 21 boys in a class. What is the ratio, in simplest terms, of the number of girls to the number of boys? (show the work please)
Answer: The simplified ratio is 4:3
Step-by-step explanation:
To find the ratio of the number of girls to the number of boys, we can divide the number of girls (28) by the number of boys (21) to get:
28 ÷ 21 = [tex]\frac{28}{21}[/tex]
Next, we can simplify the fraction further to get [tex]\frac{4}{3}[/tex], which equals 4:3.
What is the value of the expression
4x+y when x = 2 and y = 4?
2y-1
y over 11 =8 .solve for y
Answer:
y=88
Step-by-step explanation:
help i want to graduate by january :,)
Determine each measure. M
Check the picture below, tis corrected.
btw the picture is rather long, so the thumbnail here may not show all its size, so you may have to open the image in a new tab or window.
What is the area of the composite figure
Joshua wanted to know the distance between two cities. The scale on the map was 1/2 in = 10 km. The distance between the cities on the map was 2 1/4 in. What was the actual distance between the cities?
Step-by-step explanation:
remark : it is very unusual for a map to mix two measurement norms. they are normally either fully in the American or fully in the metric system.
but let's do the exercise.
the scale says 1/2 in = 10 km
but our measurement on the map brought us quarter inches.
so,
1/2 in = 2/4 in = 10 km
therefore
1/4 in = 10/2 = 5 km
now,
2 1/4 = 9/4 in
this is 9 times 1/4.
therefore, the distance between the 2 cities is
9 × 5 = 45 km.
Renee worked a total of 16 1/5 hours last week. She spent 1/3 of that time reviewing reports. How many hours did she spend reviewing reports?
Answer:
Step-by-step explanation:
First 1 ÷ 5 ×16
= 3.2
Then 3.2 × 1 ÷ 3
= 1.06
find the answer pleasere
Answer:
b is the answer f(e) gives us b
HELP PLEASE FASTTT !! ANYONE??!
Answer: The angled line on graphs!
Step-by-step explanation: :)
Hello I need help with this math it’s negative fractions so -7 1/5 - (-2/5)
Answer:
-36/5
- . 2/5-=+2/5
-36/5+2/5
34/5 or 6 4/5
Ryan needs to buy some pencils. Brand A has a pack of pencils for 7.49$ . Brand B has a pack of pencils for 9.97$ .
Find the unit price for each brand. Then state which brand is the better buy based on the unit price.
Round your answers to the nearest cent.
Answer:
Unit Price for Brand A: $0.31 per Pencil.
Unit Price for Brand B: $0.35 per Pencil.
Brand A is the better buy.
Step-by-step explanation:
Divide 7.49 by 24 to get 0.312 and round down to 0.31.
Divide 9.97 by 28 to get 0.356 and round down to 0.35 (0.36 is too much making the price $10.08)
Compare 0.31 and 0.35. (0.31 < 0.35)
In ΔMNO, \text{m}\angle M = (6x+1)^{\circ}m∠M=(6x+1) ∘ , \text{m}\angle N = (3x-10)^{\circ}m∠N=(3x−10) ∘ , and \text{m}\angle O = (x+19)^{\circ}m∠O=(x+19) ∘ . Find \text{m}\angle N.m∠N.
Applying the triangle sum theorem, m∠N = 41°
What is the Triangle Sum Theorem?Triangle sum theorem states that the sum of the three interior angles of any triangle equals 180°.
Given the following interior angles of ΔMNO:
m∠M = (6x+1)°
m∠N = (3x-10)°
m∠O = (x+19)°
Find the value of x:
m∠M + m∠N + m∠O = 180°
Substitute6x+1 + 3x-10 + x+19 = 180
Add like terms10x + 10 = 180
10x = 180 - 10
10x = 170
Divide both sides by 10x = 17
m∠N = (3x-10)°
Plug in the value of xm∠N = 3(17) - 10
m∠N = 41°
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If [tex]a\ \textless \ b[/tex], there are three ordered pairs of positive integers [tex](a,b)[/tex] that satisfy [tex]a^{2}+b^{2}=10(123)^{2}[/tex] If two of these ordered pairs are [tex](39,387)[/tex] and [tex](201,333)[/tex]. What is the third such ordered pair?
The third ordered pair that satisfies the equation of the circle is (123, 369).
The given parameters;
[tex]a^2 + b^2 = 10(123)^2[/tex]First pair of the equation, = (39, 387)Second pair of the equation = (201, 333)The third ordered pair of the equation can be determined by using general equation of a circle;
[tex]a^2 + b^2 = r^2\\\\a^2 + b^2 = (123\sqrt{10} )^2\\\\a^2 + b^2 = (\sqrt{151290} )^2\\\\a^2 + b^2 = 151290\\\\a^2 = 151290- b^2\\\\ a= \sqrt{151290 - b^2}[/tex]
The radius of the circle is calculated as;
[tex]r^2 = 151290\\\\r = \sqrt{151290} \\\\r = 388.96[/tex]
The value of a can be obtained by randomly choosing numbers less than the radius as values of b.
[tex]b < r\\\\b < 388.96[/tex]
[tex]a = \sqrt{151290 \ - \ (387)^2} \\\\a = 39\\\\(39, \ 387)\\\\a = \sqrt{151290 \ - \ (333)^2}\\\\a = 201\\\\(201, \ 333)\\\\a = \sqrt{151290 \ - \ (369)^2}\\\\a = 123\\\\(123, \ 369)[/tex]
Thus, the third ordered pair that satisfies the equation of the circle is (123, 369).
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