Answer:
Due to the higher z-score, Zach did better relative to his class.
Step-by-step explanation:
Z-score:
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.
In this question:
Whoever had the higher z-score did better:
Zach:
Scored 67, mean of 54 and standard deviation of 7, so [tex]X = 67, \mu = 54, \sigma = 7[/tex].
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{67 - 54}{7}[/tex]
[tex]Z = 1.86[/tex]
Adam:
Scored 88, mean 97, standard deviation of 6, so [tex]X = 88, \mu = 97, \sigma = 6[/tex]
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{88 - 97}{6}[/tex]
[tex]Z = -1.5[/tex]
Who did better relative to their class?
Due to the higher z-score, Zach did better relative to his class.
The University of Arizona is monitoring the spread of a bacteria by placing 100 spores of the bacteria at the start of the project. The number, P, of the bacteria is expected to grow according to the differential equation dP over dt equals the product of 0.05 times P and the quantity 1 minus P over 2000, where P t is measured in days. When does the number of bacteria reach 1000?
Answer:
In 59 days, the number of bacteria reaches 1000.
Step-by-step explanation:
Given the data in the question;
by placing 100 spores of the bacteria at the start of the project,
p(0) = 100
dP over dt equals the product of 0.05 times P and the quantity 1 minus P over 2000
dp/dt = 0.05p( 1 - p/200 )
2000dp / p( 2000 - p ) = 0.05dt
[1 / p + 1 / 200-p ]dp = 0.05 dt
Now, we integrate
∫[1 / p + 1 / 200-p ]dp = ∫ 0.05 dt
ln p - ln [2000 - p ] = 0.05 + c'
ln[ p / 2000 - p ] = 0.05 + c'
p / 2000 - p = [tex]e^{0.05t + c'[/tex]
p / 2000 - p = k[tex]e^{0.05t[/tex]
Now, since p(0) = 100, we substitute
100 / (2000 - 100) = k[tex]e^{0.05(0)[/tex]
100 / 1900 = k × [tex]e^{0[/tex]
100 / 1900 = k × 1
k = 1 / 19
Therefore,
p / 2000 - p = k[tex]e^{0.05t[/tex]
p / 2000 - p = (1/19)[tex]e^{0.05t[/tex]
when p( t ) = 1000, then t will be;
1000 / (2000 - 1000) = (1/19)[tex]e^{0.05t[/tex]
1000 / 1000 = (1/19)[tex]e^{0.05t[/tex]
1 = (1/19 ) × [tex]e^{0.05t[/tex]
1/(1/19 ) = [tex]e^{0.05t[/tex]
(1 × 19)/1 = [tex]e^{0.05t[/tex]
[tex]e^{0.05t[/tex] = 19
0.05t = ln( 19 )
0.05t = 2.9444
t = 2.9444 / 0.05
t = 58.888 ≈ 59 days
Therefore, In 59 days, the number of bacteria reaches 1000.
comments favorite math problem
You want math problems???
Answer:
Hᴇʏᴀᴀᴀ!! ᴍʏ ɴᴀᴍᴇ ɪꜱ ᴘɪɴᴋʏ ᴀɴᴅ ɪ ᴀᴍ ʜᴇʀᴇ ᴛᴏ ᴀɴꜱᴡᴇʀ ʏᴏᴜʀ Qᴜᴇꜱᴛɪᴏɴ!!ʕ ꈍᴥꈍʔ☆
Step-by-step explanation:
ɪ ᴅᴏɴ'ᴛ ʀᴇᴀʟʟʏ ʟɪᴋᴇ ᴍᴀᴛʜ ʙᴜᴛ ɪꜰ ɪ ʜᴀᴅ ᴛᴏ ᴄʜᴏᴏꜱᴇ ᴀ ꜰᴀᴠᴏʀɪᴛᴇ ɪᴛ ᴡᴏᴜʟᴅ ʙᴇ ᴀʟɢᴇʙʀᴀ!! (◕ᴗ◕✿)
ʜᴀᴠᴇ ᴀɴ ᴀᴍᴀᴢɪɴɢ ɴɪɢʜᴛ ᴏʀ ᴅᴀʏ!
*:･ﾟ✧*:･ﾟꜰʀᴏᴍ ʏᴏᴜʀ ᴏɴᴇ ᴀɴᴅ ᴏɴʟʏ ᴘɪɴᴋʏ ʕ ﾟ ● ﾟʔ✧✧･ﾟ: *✧･ﾟ:* *:･ﾟ✧*:･ﾟ
Joey opened a bank account 5 years ago with $100.
Today he has $1,000 in the account.
What is the percentage of increase?
_____%
1 rod equals how many yards
Answer:
5.5
Step-by-step explanation:
Answer:
5.5
Step-by-step explanation:
multiply the length value by 5.5
Simplify this please.
Answer:
The answer is in the picture I couldn't type it sorry.
Step-by-step explanation:
Gabriel servers 80 glasses for fruit juice for a party. He pours 2/3 cup of fruit juice into each glass. How many cups of fruit juice in fractions does Gabriel pour in all?
Answer:
53 1/3 cups
Step-by-step explanation:
if there are 80 glasses and each glass has 2/3 of juice in it, there will be 53 1/3 cups in total because 80 x 2/3 = 53 1/3
Please help me I’m so lost PLEASE NO SCAMMING
Answer:
the buttons are alredy on the calculator.
Step-by-step explanation:
What is the volume of the cylinder below?
Use 3.14 for pi.
Answer:
V = 502.4 cm³
General Formulas and Concepts:
Symbols
π (pi) ≈ 3.14Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightGeometry
Volume of a Cylinder Formula: V = πr²h
r is radiush is heightStep-by-step explanation:
Step 1: Define
r = 4 cm
h = 10 cm
Step 2: Find Volume
Substitute in variables [Volume of a Cylinder Formula]: V = (3.14)(4 cm)²(10 cm)Evaluate exponents: V = (3.14)(16 cm²)(10 cm)Multiply: V = (50.24 cm²)(10 cm)Multiply: V = 502.4 cm³A square with a side length of 30 cm is divided into 4 triangles which expression CANNOT be used to find the area of one of the four small triangles
A. 302 divided by 4
B. 1/2(30 x 15)
C. (30 x 30) divided by 2
D. 450/2
Answer: A
Step-by-step explanation:
The diagram shows a sphere with center O and a radius of 4 Inches that has been cut by a plane. The cross-section
formed by the plane is shaded.
Which shape is a possible representation of the cross section?
Answer:
A circle.
Step-by-step explanation:
Ok, any plane has a vector normal to it.
Then the plane that cuts the sphere, has a normal vector.
If we draw that normal vector such that it passes through the center of the circle, we can think of this as the "axis" of a cylinder.
Such that when we step on any point of that vector, all the points of the spere that can be reached with a perpendicular line to the vector (like the radius in polar coordinates) are at the same distance of the vector.
Then we can conclude that when we cut a sphere with a plane, the cross-section will be always a circle.
Then the shape that is a representation of the cross-section is a circle.
help me, please this is kinda hard
Answer:
[tex]x = 4.8[/tex]
Step-by-step explanation:
[tex] \frac{3}{4} = \frac{3.6}{x} [/tex]
[tex]3x = 14.4[/tex]
[tex]x = 4.8[/tex]
you need to put a, b, c, d in the right four spots
Answer:
A: Southeast
B: Northwest
C: Southwest
D: Northeast
Step-by-step explanation:
Answer:
B: Northwest
C: Southwest
D: Northeast A: Southeast
how many ways can 12 swimmers make it in first, second and third place
Answer:1320
Step-by-step explanation:Only one person can win first, second and third place. The total number of placers is 12 times 11 times 10.
Answer:
Usig their skills by:
Step-by-step explanation:
Using their strengh, force, move your feet, and arms with strong force to push you ahead faster and faster, if u are really tired I would keep going,
Why is having a variety of plants important in a ecosystem
Answer:
It is better to have a variety of plants because if the species of plants die out, the whole ecosystem becomes extinct.
Step-by-step explanation:
all the points i have left
k12 7th grade math answer them both thx
Answer:
Use geogebra it is a helpful website that helps you plot points, and find where things go. The second one is c. y=25x.
Step-by-step explanation:
A flagpole casts a 40 foot shadow. The angle of elevation grom the tip of the shadow to the tip of the flagpole is 36". How tall is the flagpole
Answer:
45/22
Step-by-step explanation:
1. At an elementary school, it's picture day. Two picture packages are available. Package 1
contains one class picture and ten wallet-size pictures for a cost of $19. Package 2 contains two
class pictures and fifteen wallet-size pictures. The cost of Package 2 is $31. Find the cost of an
individual class picture and the cost of an individual wallet-size picture.
9514 1404 393Answer:
class picture: $5wallet-size: $1.40Step-by-step explanation:
Let c and w represent the per-picture cost of the class picture and a wallet-size picture, respectively. The two packages can be described by ...
c +10w = 19
2c +15w = 31
Subtracting the second equation from twice the first, we get ...
2(c +10w) -(2c +15w) = 2(19) -31
5w = 7
w = 1.40
Substituting into the first equation, we can find the cost of a class picture.
c + 10(1.40) = 19
c = 5 . . . . . . . . . . . subtract 14
A class picture costs $5; a wallet-size picture costs $1.40.
Find the area of the composite figure. Round to the nearest tenth.
A.92.5 sq m
B. 200.5 sq m
C. 257.1 sq m
D. 596.4 sq m
Answer:
Surface area of figure = 200.52 meter²
Step-by-step explanation:
Given:
Side of square cut = 12 meter
Diameter of semi circle = 12 meter
Find:
Surface area of figure
Computation:
Diameter of semi circle = 12 meter
Radius of semi circle = Diameter of semi circle / 2
Radius of semi circle = 12 / 2
Radius of semi circle = 6 meter
Surface area of figure = Surface area of square + Surface of cylinder
Surface area of figure = [Side x Side] + πr²/2
Surface area of figure = [12 x 12] + (3.14)(6)²/2
Surface area of figure = [144] + (3.14)(36)/2
Surface area of figure = 144 + 56.52
Surface area of figure = 200.52 meter²
The freight charge on a shipment of 1200 kg is $84.00.
Which is the rate per 100 kg?
A. $0.78
B. $4.00
C. $5.70
D. $7.00
d
E. $10.08
Answer:
d
Step-by-step explanation:
The freight charge on a shipment of 1200 kg is $84.00. So, the rate per 100 kg would be $7.00. option D is correct.
What is the unitary method?The unitary method is a method for solving a problem by the first value of a single unit and then finding the value by multiplying the single value.
It is given that the freight charge on a shipment of 1200 kg is $84.00. we need to find the rate per 100 kg.
So, by the unitary method,
The freight charge on a shipment of 1200 kg = $84.00.
The freight charge on a shipment of 1 kg = 84/ 1200
The freight charge on a shipment of 100 kg = 84/ 1200
= 84 x 100/ 1200
= $7.00
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hey these are my grades and this weekend is the end of the school year I just need advice on getting my grades up
Answer:
Ask you teachers if they can give you extra assignments for extra credit! Sometimes they will!
50 POINTS !!
PLEASE HELP !! ILL GIVE BRAINLIEST TO THE RIGHT ANSWERS.
M
Answer:
72 miles
Step-by-step explanation:
To solve this problem, you can use the pythagorean theorem, which is a^2 + b^2 = c^2. We already have b equal to 54 miles, and since c is the hypotenuse, it equals 90 miles. We can substitute the values into the formula to get:
a^2 + 54^2 = 90^2
a^2 + 2916 = 8100
a^2 = 5184
a = 72 miles
Can someone please help me with these 2 questions, pleaseeeee explain them too. :) Im also giving brainliest and this is worth 15 points.
The ages of MBA students at a university are normally distributed with a known population variance of 10.24. Suppose you are asked to construct a 95% confidence interval for the population mean age if the mean of a sample of 36 students is 26.5 years. If a 99% confidence interval is constructed instead of a 95% confidence interval for the population mean, then _______________________________________________.
Answer:
too difficult 99%(95%) fraction and decimal of 26.5 and (-36)
The sides of a rectangle are in the ratio 2:5. If the longer side of the rectangle is 25.5
in., what are its width, perimeter, and area?
Answer: The width of the rectangle is 10.2 inches, the perimeter is 71.4 inches, the area is 260.1 inches.
Step-by-step explanation:
25.5/5=5.1
5.1*2=10.2
The width is 10.2 inches
25.5*2+10.2*2=71.4
The perimeter is 71.4 inches
20.5*10.2=260.1
The area is 260.1
1) The width of the rectangle is 10.2 in.
2) The perimeter of the rectangle is 71.4 in.
3) The area of the rectangle is 260.1 sq.in.
What is perimeter of rectangle?[tex]P=2\times(l+w)[/tex]
where, 'l' is the length of the rectangle
'w' is the width of the rectangle
What is the area of the rectangle?[tex]A=l\times w[/tex]
For given example,
The sides of a rectangle are in the ratio 2:5
The longer side of the rectangle is 25.5 in.
This means the length of the rectangle is [tex]l=25.5~in.[/tex]
Let 'x' represents the width of the rectangle.
⇒ [tex]\frac{2}{5} =\frac{x}{25.5}[/tex]
⇒ 2 × 25.5 = 5 × 'x'
⇒ 51 = 5x
⇒ x = 51/5
⇒ x = 10.2 in.
This means the width of the rectangle is 10.2 in.
⇒ [tex]l=25.5~in,~w=10.2~in.[/tex]
Using the formula of perimeter of the rectangle,
⇒ P = 2 × (25.5 + 10.2)
⇒ P = 2 × 35.7
⇒ P = 71.4 in.
Using the formula of area of the rectangle,
⇒ A = 10.2 × 25.5
⇒ A = 260.1 sq. in.
Therefore, the width of the rectangle is 10.2 in.
The perimeter of the rectangle is 71.4 in.
The area of the rectangle is 260.1 sq.in.
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A person invests $4000: part of the investment is at 10% interest and the rest at 12% interest. If she received $460 at the end of the year in interest, how much was invested at each rate?(whole number in dollars)
Let x be the amount invested at 10%;
SO we have;
.10x=amount invested at 10%
(4000-x).12=amount invested at 12%
So our equation would be;
.10x+(4000-x).12=460
Distribute the 12%;
.10x+480-.12x=460
Put like terms together so you can see them better;
.10x-.12x+480=460
-.02x+480=460;
subtract 480 from both sides;
-.02x=-20
Multiply each side by -.02;
x=1000
Now that we know what was invested at 10% we can subtract that from $4000 to get what was invested at 12%;
$4000-$1000=$3000
Hope you understand
=)
A triangle has side lengths of 10 cm, 24 cm, and 34 cm. Classify it as acute, obtuse, or right.
b. right
obtuse
acute
C.
Answer:
Im pretty sure the answer is C
Step-by-step explanation:
Because neither cm lengths are more than a 90 degree angle, but im not 100% sure so can you provide a picture of the problem or is that how it actually showed?
Find the range of the data.
4.8,5.5,4.2,8.9,3.4,7.5,1.6,3.8
The range is
7.3 is the range
Step-by-step explanation:
The range of a set of data is the difference between the largest and smallest values.
The value of the range of the data is,
⇒ 7.3
What is mean by Subtraction?Subtraction in mathematics means that is taking something away from a group or number of objects. When you subtract, what is left in the group becomes less.
We have to given that;
The data set is,
⇒ 4.8, 5.5, 4.2, 8.9, 3.4, 7.5, 1.6, 3.8
Since, We know that;
Difference between the highest and smallest value of the data set is called range.
Hence, We get;
The value of the range of the data is,
⇒ 8.9 - 1.6
⇒ 7.3
Thus, The value of the range of the data is,
⇒ 7.3
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2
Find the lateral area and surface area of the solid. Keep answer in exact form.
7 ft
7 ft
Lateral Area =
Surface Area =
Answer:
lateral area = 308 ft
surface area = 616 ft
just need help with C would appreciate it
Answer:
85%
Step-by-step explanation:
The students who read less than six magazines would be placed in the intervals: 0-1, 2-3, and 4-5 on the graph. Adding up the total amount in those intervals gives us:
2 + 15 = 17
So, using the answer from b, we can say that 17/20 kids read magazines. Now, we need to convert it into a percent by multiplying by 100:
17/20 *100
17 * 5
85%
The are of the triangle below is 9/20 square centimeters. What’s is the length of the base? Express your answer as a fraction in simplest form.
Answer:
6/5
Step-by-step explanation:
For this you need to clear the formula for the area which is bxh/2=A, now you need to clear the base and the formula would be b=Ax2/h, and would be (9/20)x2/ 3/4 equal to 18/20 / 3/4 and gives the result of 72/60,now you need to simplify and the simplest form is 6/5
The base of the triangle with area of 9 / 20 centimetres squared and height of 3 / 4 centimetres is 6 / 5 centimetres.
Area of a trianglearea of a triangle = 1 / 2 bh
where
b = baseh = heightTherefore,
area = 9 / 20 cm²
height = h = 3 / 4 cm
b = ?
Hence.
area of the triangle = 1 / 2 bh
9 / 20 = 1 / 2 × 3 / 4 × b
9 / 20 = 3 / 8 b
cross multiply
9 × 8 = 20 × 3b
72 = 60b
b = 72 / 60
b = 12 / 10 = 6 / 5
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