Answer:
18/a
Step-by-step explanation:
quotient means divide
18/a
You buy butter for $5.60 a pound. One portion of onion compote requires 1.7 oz of butter. How much does the butter for one portion cost? Round to the nearest cent.
Answer:
Butter per portion equals 60 cents .
Step-by-step explanation:
A pound of butter is worth $ 5.60.
5.60 dollars are converted to cents, 1 dollar equals 100 cents, then:
- One pound of butter equals 560 cents.
A portion of onion compote requires 1.7 oz of butter.
Convert 1.7 oz to pounds, so:
- 1.7 oz of butter equals 0.10625 pounds.
If a pound of butter is worth 560 cents, how much will 0.10625 pounds of butter be worth.
- Rule of 3 is used:
- 560 cents 1 pound butter
X cents 0.10625 pounds of butters
X = 560 * 0.10625
X = 59.5 cents
X = 60 cents per portion
Tickets to a school production cost $5 for a student ticket and $10 for an adult ticket. A total of 67 tickets were purchased at a cost of $440. Which value or expression could replace c in the table? 67 440 67 – a 440 – a
Answer:
Step-by-step explanation:
Keywords:
System of equations, variables, cost, tickets, adults, children.
For this case we must solve a system of equations with two variables represented by the tickets of students and adults of a school production.
We define the variables according to the given table:
a: Number of tickets sold to adults
c: Amount of tickets sold to children.
We then have the following system of equations:
A + c = 67
10a + 5c =440
From the first equation, we clear the value of the variable c:
C = 67 - a
Answer:
The value that could replace c in the table is:
C = 67 - a
Option C is the answer!
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A market survey shows that 50% of the population used Brand Z computers last year, 4% of the population quit their jobs last year, and 2% of the population used Brand Z computers and then quit their jobs. Are the events of using Brand Z computers and quitting your job independent
Answer:
the events of using Brand Z computers and quitting your job are independent.
Step-by-step explanation:
Let A be the event that the population used Brand Z computers and let B be the event that the population quit their jobs.
We are told that 50% of the population used Brand Z computers last year. Thus, the probability of event A is;
P(A) = 50% = 0.5
Also, we are told that 4% of the population quit their jobs last year. Thus the probability of event B is;
P(B) = 4% = 0.04
Since 2% of the population used Brand Z computers and then quit their jobs. Then the probability of the population used Brand Z computers and then quit their jobs is;
P(A ∩ B) = 2% = 0.02
From the law of independent events, if A and B are to be independent events, then;
P(A ∩ B) = P(A) × P(B)
Thus;
P(A ∩ B) = 0.5 × 0.04 = 0.02
This is same value as what was given in the question, thus the events of using Brand Z computers and quitting your job are independent.
Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate. Years in which U.S. presidents were inaugurated
Answer:
Interval Level of Measurement
Step-by-step explanation:
The Interval level of measurement highlights the distances between two measurements. These distances are meaningful and could be rated as low intervals or high intervals. Intervals also indicate class and order between measurements. The inauguration of the United States President is an event that occurs 72 to 78 days after the presidential election. It is usually done as a private and public oath-taking ceremony on January 20, four years after the last presidential election. So, even if the president is on a second term, this event must be held.
The last U.S presidential election occurred on January 20, 2017, and the next one will be held on January 21, 2021. So there is an interval of four years between the last and next U.S presidential inauguration ceremony.
CD is the perpendicular bisector of XY Determine the value of x. Question 8 options: A) –2 B) –1∕2 C) 4 D) 1.25
Answer:
Step-by-step explanation:
12x - 9 = 8x + 7
4x - 9 = 7
4x = 16
x = 4
solution is C
The solution is Option C.
The value of x is given from the equation x = 4
What is perpendicular bisector?A perpendicular bisector is defined as a line or a line segment that divides a given line segment into two parts of equal measurement. Lines that cross each side's midpoint and are perpendicular to the specified side are known as a triangle's perpendicular bisectors.
The perpendicular bisector theorem states that any point on the perpendicular bisector is equidistant from both the endpoints of the line segment on which it is drawn
Given data ,
Let the first line be represented as CD
Let the second line be represented as XY
Now , CD is the perpendicular bisector of XY
So , the point F is the midpoint of the line segment XY
The measure of line segment XF = 12x - 9
The measure of line segment FY = 8x + 7
From the perpendicular bisector theorem ,
The measure of line segment XF = The measure of line segment FY
Substituting the values in the equation , we get
12x - 9 = 8x + 7
Subtracting 8x on both sides of the equation , we get
4x - 9 = 7
Adding 9 on both sides of the equation , we get
4x = 16
Divide by 4 on both sides of the equation , we get
x = 4
Therefore , the value of x = 4
Hence , the value of the equation is x = 4
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RATIO AND PROPORTION PROGRAM ENHANCEMENT UNIT PAUL IS PAID 473.88 FOR 38 1/4 HOURS OF WORK WHAT AMOUNT SHOULD HE BE PAID FO 40 HOURS
Answer:
495.56 should be p[aid for 40 hours.
Step-by-step explanation:
concept used
In ratio
a:b = c:d
__________________________________________
Given
IS PAID 473.88 FOR 38 1/4 HOURS OF WORK
38 1/4 hour = 38.25 hours
if we get ratio for payment per hour
we have
473.88 / 38.25 or 473.88 : 38.25
___________________________________
now we have to find payment for 40 hours
let that payment be x
thus, ratio for payment per hour in this case will be
x/40 or x:40
since
x:40 and 473.88 : 38.25 is representative of same program enhancement unit both ratio will be equal
thus
x:40 = 473.88 : 38.25
x/40 = 473.88 / 38.25
=> x = 40*(473.88 / 38.25 ) = 495.56
Thus, 495.56 should be p[aid for 40 hours.
If x represents the rate that Joy traveled at for the first half of the trip, write an
expression that represents the amount of time it takes Joy to complete the second half of the
trip at the slower rate.
Answer:
time taken for trip 2nd half > time taken for trip 1st half
Step-by-step explanation:
Let the total distance of Joy's trip be = D
Then, the first half distance travelled = D/2
The rate (speed) at which Joy travels during first half = x
So, time taken to travel first half = Distance / Speed
= (D/2) / x = D / 2x
Second half of trip distance travelled = remaining D/2Let the rate (speed) at which Joy travels during second half = x'
As given, x' (second half speed) < x (first half speed)
So, time taken to travel first half = Distance / Speed
(D/2) / x' = D / 2x'
As x' < x : D / 2x' > D / 2x .
Trip 1st half Time taken trip < 2nd half ; or trip 2nd half time taken > 1st half
coefficient of 8x+7y
Answer:
8
Step-by-step explanation:
Identify the exponents on the variables in each term, and add them together to find the degree of each term.
8x→1
7y→1
The largest exponent is the degree of the polynomial.
1
The leading term in a polynomial is the term with the highest degree.
8x
The leading coefficient of a polynomial is the coefficient of the leading term.
____________________________________________________________
The leading term in a polynomial is the term with the highest degree.
8x
The leading coefficient in a polynomial is the coefficient of the leading term.
8
List the results.
Polynomial Degree: 1
Leading Term: 8x
Leading Coefficient: 8
Hope This Helps!!!
The average value of a function f(x, y, z) over a solid region E is defined to be fave = 1 V(E) E f(x, y, z) dV where V(E) is the volume of E. For instance, if rho is a density function, then rhoave is the average density of E. Find the average value of the function f(x, y, z) = 5x2z + 5y2z over the region enclosed by the paraboloid z = 9 − x2 − y2 and the plane z = 0.
Answer:
An aluminum bar 4 feet long weighs 24 pounds
Step-by-step explanation:
Which equation demonstrates the additive identity property?
Answer:
See Explanation
Step-by-step explanation:
The options are not given; however, you can take a clue from my explanation to answer your question
Let x be a real number;
Additive identity property implies that; adding x to 0 or 0 to x gives x;
In other words;
[tex]x + 0 = x[/tex]
[tex]0 + x = x[/tex]
Note that x can be replaced with any real number; Take for instance
[tex]1 + 0 = 1[/tex]
[tex]0 + 2.5 = 2.5[/tex]
[tex]3 + 0 = 3[/tex]
There are uncountable number of examples;
However, take note that adding 0 to a given digit results in the exact digit and that's the implication of addition identity property
Answer:
(7+4i)+0=7+4i
Step-by-step explanation:
PLEASE HELP WILL GIVE BRAINLIEST AND THX Which ratios have a unit rate of 3? Choose all that apply. 15/2 cups: 2 1/2 cups 1 cup: 1/4 cups 2/3 cups: 1 cup 3 3/4 cups: 2 cups 2 cups: 2/3 cups 2 1/2 cups: 5/6 cups
Answer:
15/2 cups: 2 1/2 cups
2 cups: 2/3 cups
2 1/2 cups: 5/6 cups
Step-by-step explanation:
Take and divide each by the smaller number
15/2 cups: 2 1/2 cups
First put in improper fraction form
15/2 : 5/2
Divide each by 5/2
15/2 ÷ 5/2 : 5/2 ÷5/2
15/2 * 2/5 : 1
3 :1 yes
1 cup: 1/4 cups
Divide each by 1/4 ( which is the same as multiplying by 4)
1*4 : 1/4 *1
4 : 1 no
2/3 cups: 1 cup
Divide each by 2/3 ( which is the same as multiplying by 3/2)
2/3 * 3/2 : 1 * 3/2
1 : 3/2 no
3 3/4 cups: 2 cups
Change to improper fraction
( 4*3+3)/4 : 2
15/4 : 2
Divide each side by 2
15/8 : 2/2
15/8 : 1 no
2 cups: 2/3 cups
Divide each side by 2/3 ( which is the same as multiplying by 3/2)
2 * 3/2 : 2/3 *3/2
3 : 1 yes
2 1/2 cups: 5/6 cups
Change to an improper fraction
( 2*2+1)/2 : 5/6
5/2 : 5/6
Divide each side by 5/6( which is the same as multiplying by 6/5)
5/2 * 6/5 : 5/6 * 6/5
3 : 1 yes
The 15/2 cups: 2 1/2 cups, 2 cups: 2/3 cups, and 2 1/2 cups: 5/6 cups have a unit rate of 3
What is the ratio?It is defined as the comparison between two quantities that how many times the one number acquires the other number. The ratio can be presented in the fraction form or the sign : between the numbers.
For checking: 15/2 cups: 2 1/2 cups
= (15/2)/(5/2) [2(1/2) = 5/2]
= 3
For checking: 1 cup: 1/4 cups
= 1/(1/4)
= 4
For checking: 2/3 cups: 1 cup
=(2/3)/1
= 2/3
For checking: 3 3/4 cups: 2 cups
= (15/4)(2)
= 15/8
For checking: 2 cups: 2/3 cups
= (2)/(2/3)
= 3
For checking: 2 1/2 cups: 5/6 cups
= (5/2)/(5/6)
= 3
Thus, the 15/2 cups: 2 1/2 cups, 2 cups: 2/3 cups, and 2 1/2 cups: 5/6 cups have a unit rate of 3
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There are 47 contestants at a national dog show. How many different ways can contestants fill the first place, second place, and third place positions?
Answer:
97290
Step-by-step explanation:
47 different people can win first
47
Now there are only 46 people left
46 different people can win second
46
45 different people can win third
47*46*45
97290
_Thirty-two holes are drilled in rows on a metal block. The number of rows is more than the number of holes in each
row. Find the number of row. (a)7 (b)25(c)67
(d)4 (e) 12
_
Answer:
D
Step-by-step explanation:
Let the number of rows be x
And the numbers of holes in each be y
xy = 32
x and y must be factors of 32
From options stated
4 is the only factor of 32
Hence option D is correct
A truck carries 360 crates of avocados to a grocery distribution center. If there are 8640 avocados total, how many avocados are in each crate?
Answer:
There are 24 avocados in each crate.
Step-by-step explanation:
This is a division problem.
8640/360 = 24
There are 24 avocados in each crate.
if pentagon OPQRS is dilated by a scale factor or ?
from the origin to create O'P'Q'R'S: what is the ordered pair of point S'?
Answer:
Option (D) : (3.5, 8.75)
I don't understand word problems can someone please answer it for me and I need it ASAP.
Answer:
Inequality: 3 + 1.2c
What you'd put on graph: 1 ≥ 13.50
Suppose 50 percent of the customers at Pizza Palooza order a square pizza, 70 percent order a soft drink, and 35 percent order both a square pizza and a soft drink.
Required:
Is ordering a soft drink independent of ordering a square pizza? Explain
Answer:
Ordering a soft drink is independent of ordering a square pizza.
Step-by-step explanation:
20% more customers order a soft drink than pizza, therefore they cannot be intertwined.
Given: P(A)=0.5 & P(B)=.7
P(A∩B) = P(A) × P(B)
= 0.5 × .7
= 0.35
P(A∪B) = P(A) + P(B) - P(A∩B)
= 0.5 + .7 - 0.35
= 0.85
P(AΔB) = P(A) + P(B) - 2P(A∩B)
= 0.5 + .7 - 2×0.35
= 0.5
P(A') = 1 - P(A)
= 1 - 0.5
= 0.5
P(B') = 1 - P(B)
= 1 - .7
= 0.3
P((A∪B)') = 1 - P(A∪B)
= 1 - 0.85
= 0.15
Yes ordering a soft drink is independent of ordering a square pizza.
We have given 50 percent of the customers at Pizza Palooza order a square pizza, 70 percent order a soft drink, and 35 percent order both a square pizza and a soft drink.
Let A: denote pizza
B: Soft drink
Then,
P(A)=0.5 and P(B)=0.7
And P(A∩B) = P(A) × P(B)
= 0.5 × 0.7
= 0.35
We know P(A∪B) = P(A) + P(B) - P(A∩B)
= 0.5 + 0.7 - 0.35
= 0.85
P(AΔB) = P(A) + P(B) - 2P(A∩B)
= 0.5 + 0.7 - 2×0.35
= 0.5
Also we know P(A') = 1 - P(A)
= 1 - 0.5
= 0.5
And P(B') = 1 - P(B)
= 1 -0.7
= 0.3
And P((A∪B)') = 1 - P(A∪B)
= 1 - 0.85
= 0.15
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Ted has to gift wrap a box of chocolates that is shaped like a triangular prism. What is the minimum amount of wrapping paper he needs?
Answer:
69.48 square inches
Step-by-step explanation:
The amount of wrapping paper needed = surface area of the triangular prism
Surface area of triangular prism is given as, area = Perimeter of triangular base*height of prism + 2(base area)
Perimeter of triangular base = sum of the 3 sides of the prism
Perimeter of base = 3.5 + 3.5 + 3 = 10 inches
Height of prism = 6 inches
Base area = ½*base of triangle * height of triangle = ½*3*3.16 = 4.74 in²
Surface area of triangular prism = [tex] 10*6 + 2(4.74) [/tex]
[tex] S.A = 60 + 9.48 = 69.48 in^2[/tex]
Amount of wrapping paper needed is 69.48 square inches .
Two samples from the same population both have M = 84 and s2 = 20, but one sample has n = 10 and the other has n = 20 scores. Both samples are used to evaluate a hypothesis stating that μ = 80 and to compute Cohen’s d. How will the outcomes for the two samples compare?
Complete Question
Two samples from the same population both have M = 84 and s2 = 20, but one sample has n = 10 and the other has n = 20 scores. Both samples are used to evaluate a hypothesis stating that μ = 80 and to compute Cohen’s d. How will the outcomes for the two samples compare?
a.
The larger sample is more likely to reject the hypothesis and will produce a larger value for Cohen’s d.
b.
The larger sample is more likely to reject the hypothesis, but the two samples will have the same value for Cohen’s d.
c.
The larger sample is less likely to reject the hypothesis and will produce a larger value for Cohen’s d.
d.
The larger sample is less likely to reject the hypothesis, but the two samples will have the same value for Cohen’s d.
Answer:
The Cohen's d value is [tex]d = 0.895[/tex]
The correct option is b
Step-by-step explanation:
From the question we are told that
The sample mean of each population is [tex]M = 84[/tex]
The variance of each population is [tex]s^2 = 20[/tex]
The first sample size is [tex]n_1 = 10[/tex]
The second sample size is [tex]n_2 = 20[/tex]
The null hypothesis is [tex]H_o : \mu = 80[/tex]
Generally the standard deviation is mathematically evaluated as
[tex]s = \sqrt{20 }[/tex]
=> [tex]s = 4.47[/tex]
The first test statistics is evaluated as
[tex]t_1 = \frac{M - \mu }{ \frac{\sigma }{ \sqrt{n_1} } }[/tex]
=> [tex]t_1 = \frac{84 - 80 }{ \frac{4.47 }{ \sqrt{10} } }[/tex]
=> [tex]t_1 = 2.8298[/tex]
The second test statistics is evaluated as
[tex]t_2 = \frac{M - \mu }{ \frac{\sigma }{ \sqrt{n_2} } }[/tex]
=> [tex]t_2 = \frac{84 - 80 }{ \frac{4.47 }{ \sqrt{20} } }[/tex]
=> [tex]t_2 = 4.0[/tex]
The sample with the larger test statistics (sample size) will more likely reject the null hypothesis
Generally the Cohen's d value is mathematically evaluated as
[tex]d = \frac{M - \mu }{s }[/tex]
=> [tex]d = \frac{ 84 - 80 }{4.47 }[/tex]
=> [tex]d = 0.895[/tex]
Given that the the sample mean and sample size are the same for both sample the Cohen's d value will be the same
Which represents a measure of volume?
O 5 cm
O 5 square cm
05 cm
05 cm
Answer:
5 cm³
Step-by-step explanation:
The correct options to the given question will be:
5 cm³ 5 square cm 5 cm 5 cm²The volume of a solid is referred to as the space that the figure occupies. The three dimensions are covered and recorded to measure the volume. It is measured by multiplying the length, breadth, and the height of the solid. Since three units are multiplies, therefore the unit of the volume becomes a cubic unit. Usually, the volume is measured in cubic meter or cubic centimetre.
A group of pirates captures Kevin, Lisa, Matt and Neal, and forces them to play a game. They each roll a fair 6-sided-die once. If the product of their roll is a multiple of 3, they all have to walk the plank, but otherwise they are safe. What is the probability that they survive? A)2/3 B)16/81 C)145/1296 D)65/81 E)625/1296 PLZ answer been waiting. I'll give 30 points
Answer: Option B, 16/81
Step-by-step explanation:
So we have 4 prisoners, they will roll a fair six side die and the product of the four rolls must NOT be a multiple of 3.
We know that every integer number can be "decomposed" into a product of prime numbers.
Then a number N, that is divisible by 3, can be written as:
N = 3*k
Where k is another integer.
Here we will have a product of 4 numbers, each of them are in between 1 and 6.
Now, if only one of the prisoners rolls a 3, then the product of the rolls will always be a multiple of 3. And if one of the rolls is 6 the same will happen, because 6 = 3.2
Then the probability of surviving is when in none of the four rolls we have a 3 or a 6.
Then we must have a 1, 2, 4 or 5.
The probability of 4 outcomes out of 6, is:
P = 4/6.
But we have 4 rolls, so we have that probability four times, and the joint probability will be equal to the product of the probabiliities for each roll, then the probability of surviving is:
P = (4/6)^4 = (2/3)^4 = 16/81
Answer:
16
Step-by-step explanation:
Does anyone have the solution to this
Step-by-step explanation:
There is 1 root at x = 1, where the function crosses the x-axis.
There are 2 roots at x = -2, where the function touches the x-axis but does not cross.
So there are 3 real roots total.
The function is:
y = (x − 1) (x − (-2))²
y = (x − 1) (x + 2)²
jeff buys 44 watermelons, he gets into a car accident and loses 31, how many does jeff have left
Answer:
Jeff has 3 watermelons left
Step-by-step explanation:
44-31=13 watermelons
Answer:
13
Step-by-step explanation:
44
-31
13
Assume that thermometer readings are normally distributed with a mean of 0C and a standard deviation of 1.00C. A thermometer is randomly selected and tested. For the case below, draw a sketch, and find the probability of the reading. (The given values are in Celsius degrees.) Between and
Answer: 0.0546 and 0.9829
Step-by-step explanation:
solution:
= P( 1.50< Z <2.25 )
= P(Z <2.25 ) - P(Z <1.50 )
Using z table,
= 0.9878-0.9332
=0.0546
b.
= P( -2.12< Z <3.73 )
= P(Z <3.73) - P(Z <-2.12 )
Using z table,
= 0.9999-0.0170
=0.9829
Which polynomial function has zeros when ? A: B: C: D:
i will give brainliest and 5 stars if you help ASAP
Consider exponential function h.
h(x) = 3x + 4
The function is always positive.
(0,5) is the y-intercept, since the graphed line never crosses the x axis, there is no x-intercept.
The function is positive and greater than 4 for all values of x
Not sure what the actual choices are on a couple of the questions. The choices would help answering.
A researcher wishes to see if the average weights of newborn male infants are higher than the
average weights of newborn female infants. She selects a random sample of 12 male infants and
finds the mean weight is 7.70 pounds. She selects a random sample of 9 female infants and finds
that the mean Leight is 7.80 pounds. Assume that the variables are normally distributed and the
population standard deviation is 0.5 for each group.
Using alpha=0.05 to test if the mean weight of the males is higher than the mean weight of the
females, the pvalue of the test is:
Answer:
The p-value is [tex]p-value = 0.62578[/tex]
Step-by-step explanation:
From the question we are told that
The sample size of male infant is [tex]n_1 = 12[/tex]
The sample size of female infant is [tex]n_2= 9[/tex]
The sample mean of male infant is [tex]\= x_1 = 7.70 \ lb[/tex]
The sample mean of female infant is [tex]\= x_2 = 7.80 \ lb[/tex]
The population standard deviation is [tex]\sigma = 0.5[/tex]
The significance level is [tex]\alpha = 0.05[/tex]
The null hypothesis is [tex]H_o : \mu_ 1 = \mu_2[/tex]
The alternative hypothesis is [tex]H_1 : \mu_1 > \mu_2[/tex]
The test statistics is mathematically represented as
[tex]t =\frac{\= x_1 - \= x_2 }{\sqrt{\frac{\sigma }{n_1} } + \frac{\sigma }{n_2} } }[/tex]
=> [tex]t = \frac{7.70 -7.80}{\sqrt{\frac{0.5 }{12} } + \frac{0.5 }{9} } }[/tex]
=> [tex]t = -0.3207[/tex]
From the z-table the p-value is obtained, the value is
[tex]p-value = P(Z > -0.3207) = 0.62578[/tex]
[tex]p-value = 0.62578[/tex]
HELPP PLEASEE ��2222 is the diameter of a circle. The coordinates are �(−2, −3) and �(−12, −5). At what coordinate is the center of the circle located? A. (5, 1) B. (−5, −1) C. (−4, −7) D. (−7, −4)
Answer:
(-7, -4) which is your answer D in the list of options
Step-by-step explanation:
The center of the circle should be located half way in between the given points on the plane.
Then the center ahs to be located half way for the x coordinates of both points:
half way between -12 and -2 (notice that there is a difference of 10 units between them), therefore half way would be at 5 units to the right from the furthest point, that is -12 + 5 = -7
Similarly, for the y coordinate, we see that the difference is between -5 and -3 (a difference of two units) therefore the center point will be located half way (that is one unit) up from the lowest y coordinate: -5 + 1 = -4
Then the center of the circle is located at (-7, -4)
Question on Statistics and Confidence Intervals
A field test for a new exam was given to randomly selected seniors. The exams were graded, and the sample mean and sample standard deviation were calculated. Based on the results, the exam creator claims that on the same exam, nine times out of ten, seniors will have an average score within 5% of 75%.
Is the confidence interval at 90%, 95%, or 99%? What is the margin of error? Calculate the confidence interval and explain what it means in terms of the situation. (10 points)
The phrasing "nine times out of ten" means 9/10 = 0.90 = 90% is the confidence level. We're confident 90% of the time that the confidence interval captures the population parameter we're after (in this case mu = population mean)
The portion "have an average score within 5% of 75%" means that 75% = 0.75 is the center of the confidence interval, and it goes as low as 0.75 - 0.05 = 0.70 and as high as 0.75 + 0.05 = 0.80
This confidence interval is from 70% to 80%, meaning that nine times out of ten, we're confident that the average score is between 70% and 80%
We write the confidence interval as (0.70, 0.80). It's common to use the notation (L, U) to indicate the lower (L) and upper (U) boundaries. You might see the notation in the form L < mu < U. If so, then it would be 0.70 < mu < 0.80; either way they mean the same thing.
The margin of error is 0.05 as its the 5% radius of the interval. It tells us how far the most distant score is from the center (75%)
=========================================
In summary, we have these answers
confidence level = 90%margin of error = 5% = 0.05confidence interval = (0.70, 0.80)interpretation = We're 90% confident that the average exam score is between 0.70 and 0.80