Answer:
a. The birth length at the 2.5th percentile is approximately 18.74 inches.
b. The birth length at the 97.5th percentile is about 22.26 inches.
c. The z-score for the length at the 2.5th percentile is [tex] \\ z = -1.96[/tex].
d. The z-score for the length at the 97.5th percentile is [tex] \\ z = 1.96[/tex].
Step-by-step explanation:
We have the following information from the question:
[tex] \\ \mu = 20.5[/tex] inches.[tex] \\ \sigma = 0.90[/tex] inches.Birth lengths is a random variable and follows a normal (or Gaussian) distribution.Briefly, we can say that:
A percentile is a value x in the distribution for which a p% of the observations are below it, and (1 - p%) is above it.We can use the standard normal table whose values come from the cumulative standard normal distribution to solve this question.Preliminaries
The standard normal distribution is a normal distribution with [tex] \\ \mu = 0[/tex] and standard deviation [tex] \\ \sigma = 1[/tex]. We use this distribution to find any possible probability for normally distributed data.
These values are tabulated in the standard normal table, available on the Internet or in Statistics books.
We also need to standardize raw values (x) into z-scores (or standardized values) using the formula:
[tex] \\ z = \frac{x - \mu}{\sigma}[/tex] [1]
These z-scores represent the distance from the mean, [tex] \\ \mu[/tex], in standard deviation units. They could be negative, when the standardized value is below the mean, or positive, in which case the standardized value is above the mean.
Finding the 2.5th percentile
Or the value x in the distribution where 2.5% of the observations are below it or 97.5% of the values in the distribution are above it (100 - 2.5 = 97.5).
To solve this:
First, find the value of z in the cumulative standard normal distribution for the probability of 2.5% or, to be more precise, 0.025.Second, use the formula [1].Third, with the values of z, [tex] \\ \mu[/tex] and [tex] \\ \sigma[/tex], we solve [1] for x.Finally, x is the percentile asked in the question.The first column in the cumulative standard normal distribution is the z-score with one decimal digit. The first row has the second decimal digit. Thus, we need to first find the cumulative probability of 0.025 and find the values in the first column and in the first row that corresponds to it.
These values are -1.9 and -0.06 for a cumulative probability of 0.025 or [tex] \\ z = -1.96[/tex] for [tex] \\ P(z<0.025)[/tex]. This is the z-score for the length at the 2.5th percentile.
Using formula [1] (without using units):
[tex] \\ z = \frac{x - \mu}{\sigma}[/tex]
[tex] \\ -1.96 = \frac{x - 20.5}{0.90}[/tex]
Multiplying at both sides by 0.90
[tex] \\ -1.96*0.90 = \frac{x - 20.5}{0.90}*0.90[/tex]
[tex] \\ -1.96*0.90 = (x - 20.5) * \frac{0.90}{0.90}[/tex]
[tex] \\ -1.96*0.90 = (x - 20.5) * 1[/tex]
Adding 20.5 at both sides of the equation
[tex] \\ (-1.96*0.90) + 20.5 = x - 20.5 + 20.5[/tex]
[tex] \\ (-1.96*0.90) + 20.5 = x[/tex]
[tex] \\ x = (-1.96*0.90) + 20.5[/tex]
[tex] \\ x = -1.764 + 20.5[/tex]
[tex] \\ x = 18.736 \approx 18.74[/tex]
Therefore, the birth length at the 2.5th percentile is approximately 18.74 inches.
Finding the 97.5th percentile
Or the value x in the distribution where 97.5% of the observations are below it or also 0.025% of the observations in the distribution are above it (100 - 97.5 = 0.025).
We can follow the same steps as before, so:
[tex] \\ z = \frac{x - \mu}{\sigma}[/tex]
Consulting the standard normal table, [tex] \\ z = 1.96[/tex]. This is the z-score for the 97.5th percentile.
Using [1]
[tex] \\ z = \frac{x - \mu}{\sigma}[/tex]
[tex] \\ 1.96 = \frac{x - 20.5}{0.90}[/tex]
[tex] \\ (1.96 * 0.90) = x - 20.5[/tex]
[tex] \\ (1.96 * 0.90) + 20.5 = x[/tex]
[tex] \\ x = (1.96 * 0.90) + 20.5[/tex]
[tex] \\ x = 1.764 + 20.5[/tex]
[tex] \\ x = 22.264 \approx 22.26[/tex]
Thus, the birth length at the 97.5th percentile is about 22.26 inches.
Something worth noting is since the normal distribution is symmetrical, both percentiles are at the same distance from the mean but in diametrically opposite directions, a result taking into account the sign for z in each case (z = -1.96 and z = 1.96).
We can see these two percentiles in the below graph for a normal distribution with [tex] \\ \mu = 20.5[/tex] inches and [tex] \\ \sigma = 0.90[/tex] inches. The shaded values are for [tex] \\ P(x<18.74) \approx 0.025[/tex] (red) and [tex] \\ P(x>22.26) \approx 0.025[/tex] (blue). Look above for the brief explanation of percentile.
Amanda, Sarah and Bethany share the cost of a holiday in the ratio 5 : 4 : 3.
Amanda pays £235
a) Work out the total cost of the holiday.
b) Work out how much Bethany pays.
(show all your working out)
Answer:
a. £564
b. £141
Step-by-step explanation:
a. Firstly, we add up the ratios
= 5 + 4 + 3 = 12
Amanda’s share was 5
Let the total amount be £x
Thus; 5/12 * x = 235
5x = 12 * 235
x = 2820/5 = 564
The total cost of the holiday is £564
b. We want to calculate what Bethany paid
That would be 3/12 * 564 = £141
The number or expression in a power that is multiplied by itself?
Answer:
the base???
Step-by-step explanation:
Answer:
Exponent
Step-by-step explanation:
An exponent is a shorthand notation which tells how many times a number (or expression) is multiplied by itself.
Given a right triangle with acute angle of 40° and a hypothenuse length of 35 feet, find the length
of the side opposite the acute angle.
Answer:
the length of the side opposite = 20.6 feet
Step-by-step explanation:
using SOHCAHTOA
Sin 40 = opp / hyp
Sin 40 = opp / 35
opp = sin 40 x 35
opp = 20.6 feet
Find the 6th term of the arithmetic sequence -4, 0, 4, 8, … 16 -8 12 None of these choices are correct
Answer:
If you account 0 as your first term then the 6th term of the arithmetic sequence will be 20.
Step-by-step explanation:
Last season, a lacrosse player scored 41 points in 15 games.So far this season, the player has scored 24 points in 9 games.a. Does the player have a greater number of goals per game thisseason compared with last season?b. Suppose the player plays in as many games this season as lastseason and continues to score at this season’s rate. Write and solve aproportion to find the number of goals the player will score thisseason.
Answer:
1.) No
2.) 40 goals
Step-by-step explanation:
Given the following :
Last season:
Games played = 15
Points scored = 41
Current season:
Games played = 9
Points scored = 24
A)
Last season:
Goals per game = total points / number of games
Goals per game = 41 / 15 = 2.733
Current season :
Goals per game = total points / number of games
Goals per game = 24 / 9 = 2.667
Last season's goal per game is greater than that of current season.
B)
Current rate = goals / games = 24/9 - - - (1)
Let points to be scored this season = y
Ratio of y to number of games played last season = y / 15 - - - (2)
Equate both
24 / 9 = y / 15
9 * y = 24 * 15
y = 360 / 9
y = 40
A system of equations is shown below:
n = 3m + 7
n - 2m = 1
What is the solution, in the form (m, n), to the system of equations?
O (3,7)
(1,8)
O(-3,-2)
O(-6, -11)
Answer:
Last option is the correct choice.
Step-by-step explanation:
Substitute the first equation in the second equation and then solve for the variable m.
[tex]\begin{bmatrix}3m+7-2m=1\end{bmatrix}[/tex]
[tex]m=-6[/tex]
[tex]n=3\left(-6\right)+7\\\\n=-11[/tex]
Best Regards!
D!!!!
n=−11
m=−6
I used a graph to show you what the lines and when they would intersect would look like!!
What is the solution to the system of linear equations graphed below?
A.) (0, 4)
B.) (4, 1/2)
C.) (1/2, 4)
D.) (0, 3)
Answer:
C.) (1/2, 4)
Step-by-step explanation:
The solution is where the two lines intersect
The lines intersect at x = .5 and y =4
Answer:
C.) (1/2, 4)
Step-by-step explanation:
A high school has 44 players on the football team. The summary of the players' weights is given in the box plot. What is the interquartile range of the players' weights? 150 160 170 180 190 200 210 220 230 240 250 260 270 [infinity] −[infinity] 262 160 175 214 225 Weight (in pounds)
Answer:
The interquartile range of the players' weights = 48 pounds.
Step-by-step explanation:
The boxplot attached to this question is missing. It was obtained online and is attached to this solution of the question.
It should be noted that the following is true for a boxplot.
A box plot gives a visual representation of the distribution of the data, showing where most values lie and those values that greatly differ from the rest, called outliers.
The elements of the box plot are described thus;
The bottom side of the box represents the first quartile, and the top side, the third quartile. Therefore, the width of the central box represents the inter-quartile range.
The horizontal line inside the box is the median.
The lines extending from the box reach out to the minimum and the maximum values in the data set, as long as these values are not outliers. The ends of the whiskers are marked by two shorter horizontal lines.
Variables in the dataset, higher than Q3+(1.5×IQR) or lower than Q1-(1.5×IQR) are considered outliers and are usually shown using dots above the top whisker or below the bottom whisker.
So, it is evident that for this question,
First quartile = 174 pounds
Third quartile = 222 pounds
Inter Quartile Range = (Third quartile) - (First quartile)
= 222 - 174
= 48 pounds.
Hope this Helps!!!
The width of a photograph is 4 inches. Tori measures its width using the two rulers, both of which measure in inches. Which statement is true about the accuracy and precision of the rulers? The measurement found using Ruler 1 is more accurate and more precise. The measurement found using Ruler 2 is more accurate and more precise. The measurement found using Ruler 1 is more accurate but less precise. The measurement found using Ruler 1 is more precise but less accurate.
Answer:
The measurement found using Ruler 2 is more accurate and more precise.
Step-by-step explanation:
Ruler 1 has fewer tick marks, Ruler 2 has more which indicates a more precise, exact, accurate reading.
option B is correct on edge
Step-by-step explanation:
Please answer this in two minutes
Answer:
[tex] t = 17.3 [/tex]
Step-by-step explanation:
Given:
∆TUV,
m < T = 87°
VT = u = 11
TU = v = 14
VU = t = ?
Use the Law of Cosines to find t as shown below:
[tex] t^2 = u^2 + v^2 - 2uv*cos(T) [/tex]
[tex] t^2 = 11^2 + 14^2 - 2*11*14*cos(87) [/tex]
[tex] t^2 = 121 + 196 - 308*0.0523 [/tex]
[tex] t^2 = 317 - 16.1084 [/tex]
[tex] t^2 = 300.89 [/tex]
[tex] t = 17.3 [/tex] (rounded to the nearest tenth)
He science club has 4 members. The club bought b bumper stickers to split among its members. Write an expression that shows how many bumper stickers each member will get
Answer:
b / 4
Step-by-step explanation:
If you are splitting b bumper stickers between 4 members, you must divide the number of bumper stickers by the number of members, which is 4! Dividing is just like if you were to divvy something up between people, but it is a mathematical term! This will give you b / 4.
A
a
29
20
С
B
21
Find tan(a) in the triangle.
Answer:
21/20.
Step-by-step explanation:
tan α = opposite side / adjacent side
= 21/20
What is 6 y minus 3 x = negative 18 written in slope-intercept form?
Answer:because that’s what the answer is
Step-by-step explanation:
Answer:
Y=1/2x-3
Step-by-step explanation:
Express in the form 1 : n 4 : 12
Answer:
1:3
Step-by-step explanation:
4:12 divides by 4 to give
1 : 3
Answer:
n = 3
Step-by-step explanation:
1:n = 4:12
1/n = 4/12
Cross multiply.
4n = 12
n = 12/4
n = 3
PLEASE HELP ME! IM REALLY CONFUSED!
Order the following numbers from least to greatest. 5/4; 1.3; 1 8/25 (The 1 8/25 is a mixed number reading One and Eight Twenty-fifths, not 18/25)
Answer:
5/4,1.3,1 8/25
Step-by-step explanation:
5/4 = 1.25
1 8/25=1.32
1.25<1.3<1.32
What is the inverse of the function f(x) = 2x + 1?
1
o h(x) = 5x-
2x +
O h(x) = 1
3x-2
N/" Nr
Oh(x) =
O h(x) = x + 2
Answer:
[tex]f^{-1}[/tex] (x) = [tex]\frac{x-1}{2}[/tex]
Step-by-step explanation:
let y = f(x) and rearrange making x the subject, that is
y = 2x + 1 ( subtract 1 from both sides )
y - 1 = 2x ( divide both sides by 2 )
[tex]\frac{y-1}{2}[/tex] = x
Change y back into terms of x with x = [tex]f^{-1}[/tex] (x) , so
[tex]f^{-1}[/tex] (x) = [tex]\frac{x-1}{2}[/tex]
Answer: " f⁻¹(x) = (x-1)/2 "; or, write as:
___________________________________
" f⁻¹(x) = (x/2) - (1/2) " .
___________________________________
Step-by-step explanation:
___________________________________
Given: f(x) = 2x + 1 ; Find the inverse:
___________________________________
1) Rewrite as y = 2x + 1 ;
2) Replace the "x" with "y" ; and the "y" with "x" ; and rewrite:
x = 2y + 1 ;
3) Now, "solve"; with "y" standing alone as a single, isolated variable on the left side of the equation, with an "equals" sign following the "y" :
x = 2y + 1 :
Subtract "1" from each side of the equation:
x - 1 = 2y + 1 - 1 ;
to get:
x - 1 = 2y ;
___________________________________
↔ Rewrite as :
2y = x - 1 ;
Now, divide each side of the equation by "2" ;
to isolate "y" on the left-hand side of the equation;
& to solve in terms of "y":
___________________________________
2y / 2 = (x-1)/2 ;
___________________________________
to get:
y = (x-1)/2 ;
or; write as: y = (x/2) - (1/2);
___________________________________
Now, rewrite; by replacing the "y" with "f⁻¹(x) "; as follows (to indicate that this is the "inverse function"):
___________________________________
f⁻¹(x) = (x-1)/2 ; or, write as:
___________________________________
f⁻¹(x) = (x/2) - (1/2) .
___________________________________
Hope this is helpful to you!
Best wishes!
___________________________________
Triangles X Y Z and E G F are shown. Side X Y is 3.0 inches and angle Y Z X is 107 degrees. Side F G is 2.4 inches and side E F is 1.3 inches. Angle G E F is 48 degrees. Given ΔXYZ ≅ ΔEGF, find the measurements of the unknown sides and angles. ZX = 1.3 in. EG = 3 in. m∠X = ° m∠G = °
Answer:
The answer is given below
Step-by-step explanation:
In triangle EFG, let a = EG, A = ∠f, b= 1.3 in, B = ∠G, c = 2.4 in C = ∠E = 48°
Using cosine rule:
[tex]c^2=a^2+b^2-2ab*cos(C)\\a^2-2ab*cos(C)=c^2-b^2\\Substituting:\\a^2-2a(1.3)cos(48)=2.4^2-1.3^2\\a^2-1.74a=4.07\\a^2-1.74a-4.07=0\\a=3\ or\ -1.34\\a=EG=3\ inches[/tex]
EG = 3 inches
Using sine rule,
[tex]\frac{b}{sin(B)} =\frac{c}{sin(C)}\\ Substituting:\\\frac{1.3}{sin(B)} =\frac{2.4}{sin(48)}\\sin(B)=\frac{sin(48)*1.3}{2.4}=0.4025\\ B=sin^{-1}(0.4025)=23.7^0[/tex]
∠G = B = 23.7°
Given ΔXYZ ≅ ΔEGF,
Therefore: ZX = EF = 1.3 inches, m∠X = m∠G =23.7 °, m∠Z = m∠F = 107°
ZY = FG = 2.4
Answer:
ZX = 1.3 in.
EG = 3 in.
m∠X = 48°
m∠G = 25°
Step-by-step explanation:
ΔXYZ ≅ ΔEGF
107 + 48 = 155
m∠G = 180 - 155 = 25
HELP ASAP ! Identify the volume and surface area of a sphere in terms of pi with a great circle area of 144pi ft^2.
Answer:
Area of sphere = 576 pi ft^2
Volume of sphere = 2,304 pi ft^3
Step-by-step explanation:
Radius of great circles are the same as radius of the sphere
So let’s calculate the radius of the sphere from the area given;
Mathematically;
pi * r^2 = 144pi
r^2 = 144
r = square root of 144
r = 12 ft
Volume of sphere = 4/3 * pi * r^3
= 4/3 * pi * 12^3 = 2,304 pi ft^3
Area of sphere = 4 * pi * r^2 = 4 * pi * 12^2 = 4 * 144 * pi = 576 pi ft^2
find the slope between (-5,-4) and (-12,7)
Answer:
Slope = [tex]-\frac{11}{7}[/tex]
Step-by-step explanation:
Slope = [tex]\frac{rise}{run}[/tex]
Slope = [tex]\frac{y2-y1}{x2-x1}[/tex]
Slope = [tex]\frac{7+4}{-12+5}[/tex]
Slope = [tex]\frac{11}{-7}[/tex]
Slope = [tex]-\frac{11}{7}[/tex]
Answer:
11/-7
Step-by-step explanation
- First you get you X1 and Y1 then X2 and Y2
-after getting that your problem should look like this:
7 minus negative 4
over negative -12 minus negative -5
which when subtracted will get you 11/-7!
please give brainliest!
I need help with this what’s the answer
Answer:
If we look at the table we notice that 2 + 4 = 6, 3 + 4 = 7, 4 + 4 = 8 and so on so the equation is y = x + 4.
Answer:
x+4
Step-by-step explanation:
To solve this question we must look at the examples :
x=2 and y=66-2=4
x=2 and y=77-3=4
so the aswer is : y = x + 4
Estimate the product of the numbers 908 x 67 by rounding each number to the nearest hundred. The estimated product is ?
Work Shown:
908 rounds to 900. This is because 908 is closer to 900, than it is to 1000.
While 67 rounds to 100, for similar reasoning as above.
Multiplying those rounded values gives 900*100 = 90,000. This is the number 90 thousand.
Note that 9*1 = 9 and its followed by four zeros (two each from 900 and 100). This is a quick way to mentally multiply things like this.
Using a calculator, we see that 908*67 = 60,836 which is fairly off from what we estimated. This is to be expected as estimates only give us a rough idea of how big a number is.
Which graph represents a function with direct variation?
Answer:
a direct variation means that the ratio of the variables is constant.as we know y=kxrepresents a family of straight lines passing through the origin.
Step-by-step explanation:
thisthis means as x increases y increases and aspects decreases y increases and the ratio between them always stayed the same
Answer:
A direct variance implies that the ratio of the variables is constant, since we know that y= kx represents a straight line family that passes through the origin.
What is the product?
Answer:
It's (B)
Step-by-step explanation:
Pls help me it is urgent .A trader bought a plate for 120 naira and sold it for 168 naira .What is his percentage profit.
Answer:
40%
Step-by-step explanation:
He made 48 naira.
48 = 40% * 120
1/3 of 12 =2/3 of PLEASE HELP ME!!!!!!!!!!!
Answer:
6
Step-by-step explanation:
Let the number be x.
1/3 × 12 = 2/3 × x
Multiply.
12/3 = 2/3x
4 = 2/3x
Multiply both sides by 3/2.
4 × 3/2 = x
12/2 = x
x= 6
Answer:
1/3 of 12 = 2/3 of 6
Step-by-step explanation:
1/3 · 12 = 2/3 · x
12/3 = 2x/3
Multiply 3 on both sides.
12 = 2x
12 ÷ 2 = x
6 = x
Will give high vote and brainliest!! Just make sure to put the CORRECT answer <3 (the one i clicked is wrong)
Answer:
1.2x10^13
Step-by-step explanation:
Trillion=1x10^12
12 trillion=12x10^12
12 trillion=1.2x10^13
Your mom about a multi-pack of hot fries from Sam's Club last week. When you got home from school your brother and his friends has eaten 1/6 of the bags. By the end of the week your family had eaten 50% of what was left. There were 30 bags of hot fries left in the Box how many were in the box to begin with
Answer:
Ans is 72 bags!!
Step-by-step explanation:
Call the original number of bags, B
After 1/6 of these were eaten, there were B - (1/6)B = (5/6)B left
After 50% of these were eaten.....there were (1/2)(5/6)B = (5/12)B left
And this = 30
So
(5/12)B = 30 multiply both sides by 12/5
B = 30(12/5)
B = 360 / 5
B = 72
Hope it helped
Tysm
Mark me BRAINLIEST!
Identify the values of a, b, and c in the following quadratic equation. 3[tex]x^{2}[/tex] - 2x + 5 = 0
a =?
b =?
c =?
Answer:
a = 3
b = -2
c = 5
Step-by-step explanation:
The general form of a quadratic equation is ax² + bx + c = 0.
3x² - 2x + 5 = 0
The value of a is 3.
The value of b is -2.
The value of c is 5.
ITUTUS
Every day a school bus driver passes the same traffic light twice, once before school and once after.
Each time he passes the light, he records if it is red, green, or yellow.
Here is a summary of the data he got after 150 days.
Traffic light
before school
Traffic light
after school
Number of days
red
red
13
red
green
17
red
yellow
23
green
red I
11
green
green
10
green
yellow
17
yellow
red
24
yellow
green
21
yellow
yellow
14
Suppose the driver will continue recording the colors for 50 more days.
In how many of these 50 days will the light be yellow at least once? Use the data to make a prediction.
Х
$
?
Answer:
Step-by-step explanation: