Question:
The average life expectancy of people in the United States in 2018 was 78.54 years with a standard deviation of approximately 15 years.
Suppose we take a sample of 40 individuals in the United States, what are the mean and standard deviation for sample averages from samples of size 40?
Answer:
[tex]\bar x = 78.54[/tex]
[tex]\sigma_x = 2.37[/tex]
Step-by-step explanation:
Given
[tex]\mu = 78.54[/tex] --- Population mean
[tex]\sigma = 15[/tex] --- Population standard deviation
[tex]n = 40[/tex] --- Sample size
Solving (a): The sample mean
According to the central limit theorem, sample mean is always equal to the population mean.
So:
[tex]\bar x = 78.54[/tex]
Solving (b): The sample standard deviation
Using the central limit theorem, we have:
[tex]\sigma_x = \frac{\sigma}{\sqrt n}[/tex]
So:
[tex]\sigma_x = \frac{15}{\sqrt{40}}[/tex]
[tex]\sigma_x = \frac{15}{6.32}[/tex]
[tex]\sigma_x = 2.37[/tex]
i just don’t understand how to do the half circle part. so if you could just give me that number i can do the rest.
Answer:
the radius of the circle is 5 and you find the raidus of the circle by using the formula A= (pi)r squared. then you'd divide that answer by two. :)
Step-by-step explanation:
Someone plz help me plz
Answer:
i woyld say 1/3 and 2/5
Step-by-step explanation:
they aer bigger parts then the other
Answer:
if you find both areas and compare them with a common denominator youll see that 8/15 and 1/6 is greater .
A rectangular piece of land measures 250 m by 220 m. Each side is to be fenced with 3 rows of wires. What is the length of the wire needed?
Answer:
2,820 m
Step-by-step explanation:
Given that the rectangular piece of land measures 250m by 220 m, the perimeter of the rectangle gives the length of wire required to fence it once.
The perimeter p of a rectangle of length l and width b is given as
p = 2(l + b)
Hence p = 2( 250 + 220)
= 2 * 470
= 940 m
Since each side is to be fenced with 3 rows of wires, the length of wire required
= 3 * 940m
= 2,820 m
Ariana made cookies. She used 3 7/8 cups of flour and 2 1/8 cups of sugar. How much more flour than sugar did Ariana use?
Answer:
1 6/8 cups of flour
Step-by-step explanation:
Just subtract 2 1/8 from 3 7/8
What is the area of the frame in square units around the picture? 12 8 45 6s Enter the expression in the box. square units
Answer:
Step-by-step explanation:
The area of frame is 40s square units.
What is area?The measurement that conveys the size of a plane or curved surface is known as area. Surface area refers to the area of an open surface or the boundary of a three-dimensional object, whereas the area of a plane region or plane area refers to the area of a shape or planar lamina. The amount of material with a given thickness that would be required to create a model of the shape is known as area.
Given a frame whose inner dimesons are,
inner length = l₁ = 8 units
inner breadth = b₁ = 4s units
outer dimensions are,
outer length = l₂ = 12 units
outer breadth = b₂ = 6s units
area of frame = outer area - inner area
area of frame = l₂b₂ - l₁b₁
area of frame = 12(6s) - 8(4s)
area of frame = 72s - 32s
area of frame = 40s square units
Hence the area of frame is 40s square units.
Learn more about area;
https://brainly.com/question/27683633
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What is the value of | - 1/2 |
Answer:
1/2
Step-by-step explanation:
|x| is absolute value, and it can't be a negative number. It is 1/2.
write the equivalent ratio for 8 : 14
Answer:
Step-by-step explanation:
8/14: 4/7, 16/28, 32/56
help with finding g(f(x))
f(x) = x squared - 3x + 2
g(x)= x+2
Answer:
=x+2
Step-by-step explanation:
Answer:
g(f(x)) = x² - 3x + 4
Step-by-step explanation:
Substitute x = f(x) into g(x) , that is
g(x² - 3x + 2)
= x² - 3x + 2 + 2
= x² - 3x + 4
Tell whether the angles are adjacent or vertical. Then find the value of x.
Plz answer if u really know it thanks so much
I will mark Brainliest!!!!!
Answer:
600
Step-by-step explanation:
the midway point between 800 and 400 is 600
[tex] \sqrt{18} - \sqrt[x]{2 } = \sqrt{32} [/tex]
solve for x
Please Help me ive posted this like 8 times !!!!!
The freshman class of 175 students went on a field trip. For transportation, they needed both vans (which hold 5 students each) and buses (which hold 35 students each). There was a total of 11 vehicles used.
How many of each type of vehicle did they use?
Vans: _________________
and
Buses _________________
.
Answer:
You will need 7 vans and 4 buses
Step-by-step explanation:
7 vans would take care of 35
4 buses would take care of 140 kids
and it uses a total of 11 vehicles
Hope this helps
Answer:
Vans = 7
Buses = 4
Step-by-step explanation:
x = vans
y = buses
x + y = 11 (1)
5x + 35y = 175 Divide this equation by 5
x + 7y = 35 (2)
============
Subtract (1) from (2)
x + 7y = 35
x + y = 11
6y = 24 Divide by 6
6y/6 =24/6
y = 4
===========
x + y = 11
x + 4 = 11
x = 11 - 4
x = 7
Now Let's check it
x is the number of vans which holds 5 students each
7 * 5 = 35
y is the number of buses which holds 35 students each
4 * 35 =140
Total number of students = 35 + 140 = 175
So it checks.
Utilizar la recta numerica para calcular:
a) 12 + 2 =
b) 4 − 7 =
c) 8 − 2 =
d) −9 + 3 =
e) −14 + 5 =
f ) −6 − 6 =
g) −11 − 2 =
h) −3 − 8 =
Answer:
a) 14
b) -3
c) 6
d) -6
e) -9
f) -12
g) -13
h) -11
Lenora wants to build the bike ramp shown. Find the length of the base of the ramp.
Answer:
te lenght was base of the ramp
A circle has a radius of 50 cm. Which of these is closest to its area?
Answer:
Approximately 7853.98
Step-by-step explanation:
The formula to finding the area of a circle based on radius is [tex]\pi r^2\\[/tex], where r is radius. Hope this helped :D
which sequence shows the number in order from least to greatest?
please help
The triangles are similar by the AA similarity postulate. Find the value of x
Answer:
2.5
Step-by-step explanation:
We know that they are similar and that the length of the long side is 3 + 3, which is 6. 6 = 3 times 2, meaning that all values in the big triangle are double the little triangle. That means that 2x = 5, meaning that x = 2.5.
(i will give the brainlyist please help) The solution to the system is (3, 4);
30 – 2y = 1
4y= 7 + 3
True
False
Answer:
true
Step-by-step explanation:
first and second one both make sense
Find an overestimate for 33 x 67 by adjusting each factor up to the next ten.
Answer:
210 is my estimate
Step-by-step explanation:
Solve for x
4x = 51
1. x = 204
2. x = 47
3. x = 12.75
Answer:
#. x=12.75
Step-by-step explanation:
51/4
i will give brainiest to the first one
aurora scored 572 marks out of 650 belle scored 450 out of 500 for the annual examination.
a. who performed better and by how much.
b .what percentage she scored
Step-by-step explanation:
a. Belle as she only missed 50 questions where as Aurora missed 78. (500-450) and (650-572)
b. Belle scored 90% (450/500=0.9)
Answer:
a. Belle scored better, by scoring 2% more than Aurora.
b. She scored 90%
Step-by-step explanation:
Make your denominator out of a 100
So you will divide by 6,5
572÷6,5/650÷65
= 88/100
=88%
And divide the other by 5
450÷5/500÷5
=90/100
=90%
if the lenghts of the diagonals of a rhombus are 10 cm and 8 cm then its area is
Answer:
40cm square
Step-by-step explanation:
10x8cm=80 cm/2=40cm square
Answer:80cm
Step-by-step explanation:Area=[tex]\frac{dxd}{2}[/tex]
10cm x 8cm=80cm
The expression 16t² represents the distance, in feet, an object falls after t seconds. The object is dropped from a height of 906 feet.
Complete Question:
The expression 16t² represents the distance in feet an object falls after t seconds. The object is dropped from a height of 906 feet. What is the height in feet of the object 2 seconds after it is dropped?
Answer:
H(2) = 842 feet
Step-by-step explanation:
Let the height be H.
Given the following data;
H(t) = 16t²
Height, H = 906 feet
Time, t = 2 seconds
To find the time, t at 2 seconds, we would use the following formula;
H(t) = H - 16t²
H(2) = 906 - 16(2)²
H(2) = 906 - 16*4
H(2) = 906 - 64
H(2) = 842 feet
Therefore, the height in feet of the object 2 seconds after it is dropped is 842.
Marty bought a piece of material that was 68 yard long and a piece that was 48 yard long. Which statement is TRUE? A. 48> 68 B. 68< 48 C. 68> 48 D. 48= 68
Answer:
C
Step-by-step explanation:
68 is bigger than 48...
Look at the box-and-whisker plot below comparing the scores from Pre-test A and Pre-test B. What is the difference of the lower quartiles of Pre-test A and Pre-test B?
Answer:
See Explanation
Step-by-step explanation:
The question is incomplete as the box and whisker plots for the Pre-test A and the Pre-test B are not given. I will answer this question with the attached image.
The attached image contains three plots.
The first plot shows the description of how to read the box and whisker plot.
From the description image, the following represents the summary of the plot
The green line: Minimum
The blue line: Lower Quartile (Q1)
The red line: Median (Q2)
The yellow line: Upper Quartile (Q3)
The last green line: Maximum
Using the above descriptions to read the pre-test A and pre-test B plots.
The lower quartile of pre-test A is:
[tex]Pre\ test\ A = 11[/tex]
The lower quartile of pre-test B is:
[tex]Pre\ test\ B = 16[/tex]
The difference (D) is calculated as:
[tex]D = |Pre\ test\ A - Pre\ test\ B|[/tex]
[tex]D = |11 - 16|[/tex]
[tex]D = |- 5|[/tex]
[tex]D = 5[/tex]
The difference is 5
Use the above explanation to answer your question
Mathhhhhhhhhhhhhhhhhh
Answer: Question 1 is 3/4
Question 2 is the line intersecting at -9 in the y axis and the slope is 4 so the other point would go at (1,-5)
Step-by-step explanation:
HELP!! I NEED HELP ASAP
hey need help with this quick question, thanks :)
Answer:
The answer is 2
Step-by-step explanation:
just subtract the powers of 10 and 8.
Find the volume of the prism.
A drawing of a rectangular prism. It has length three-fourths meter, width one-half meter and height start fraction five over eight end fraction meter.
The volume is ____
cubic meters.
Answer:
V = 15/64 or 0.23
Step-by-step explanation:
Formula:
V = lwh
[tex]\frac{5}{8} *\frac{1}{2} *\frac{3}{4} \\V = \frac{15}{64}[/tex]
