Answer:
[tex]Mean = 68.9[/tex]
[tex]s^2 =18.1[/tex] --- Variance
Step-by-step explanation:
Given
[tex]\begin{array}{cccccc}{Class} & {51-58} & {59-66} & {67-74} & {75-82} & {83-90} \ \\ {Frequency} & {6} & {3} & {11} & {13} & {4} \ \end{array}[/tex]
Solving (a): Calculate the mean.
The given data is a grouped data. So, first we calculate the class midpoint (x)
For 51 - 58.
[tex]x = \frac{1}{2}(51+58) = \frac{1}{2}(109) = 54.5[/tex]
For 59 - 66
[tex]x = \frac{1}{2}(59+66) = \frac{1}{2}(125) = 62.5[/tex]
For 67 - 74
[tex]x = \frac{1}{2}(67+74) = \frac{1}{2}(141) = 70.5[/tex]
For 75 - 82
[tex]x = \frac{1}{2}(75+82) = \frac{1}{2}(157) = 78.5[/tex]
For 83 - 90
[tex]x = \frac{1}{2}(83+90) = \frac{1}{2}(173) = 86.5[/tex]
So, the table becomes:
[tex]\begin{array}{cccccc}{x} & {54.5} & {62.5} & {70.5} & {78.5} & {86.5} \ \\ {Frequency} & {6} & {3} & {11} & {13} & {4} \ \end{array}[/tex]
The mean is then calculated as:
[tex]Mean = \frac{\sum fx}{\sum f}[/tex]
[tex]Mean = \frac{54.5*4+62.5*3+70.5*11+78.5*13+86.5*4}{6+3+11+13+4}[/tex]
[tex]Mean = \frac{2547.5}{37}[/tex]
[tex]Mean = 68.9[/tex] -- approximated
Solving (b): The sample variance:
This is calculated as:
[tex]s^2 =\frac{\sum (x - \overline x)^2}{\sum f - 1}[/tex]
So, we have:
[tex]s^2 =\frac{(54.5-68.9)^2+(62.5-68.9)^2+(70.5-68.9)^2+(78.5-68.9)^2+(86.5-68.9)^2}{37 - 1}[/tex]
[tex]s^2 =\frac{652.8}{36}[/tex]
[tex]s^2 =18.1[/tex] -- approximated
Help me out with this
Answer:
What is 2x + 5 (y-1) when x=8 and y=5
Step-by-step explanation:
HELP ME
Answer:
40:60:80
Step-by-step explanation:
....... . ...........
Alex ate 1/3 of a pizza. Katelyn ate 2/7 of the same pizza. How much larger of a portion did Alex eat than Katelyn?
Answer:
1/21
Step-by-step explanation:
1/3 - 2/7 = 7/21 - 6/21 = 1/21
Hope I helped!
Diana and Michael, who are taking different classes, are arguing about who did better on their most recent test. Diana received a score of 92 on her History test and Michael received a 688 on his Math test. The mean test score for the History class is 71 with a standard deviation of 15.The mean test score for the Math class is 493 standard deviation of 150. Who did better, relative to other students in the same class? Justify your answer.
Answer:
Diana's score is better.
Step-by-step explanation:
In Diana case :
Score = 92
Mean score , μ = 71
Standard deviation σ = 15
So,
P( x ≥ 92 ) = 1 - P( x ≤ 92 )
= 1 - P(z ≤ [tex]\frac{x - u}{\sigma}[/tex] )
= 1 - P( z ≤ [tex]\frac{92 - 71 }{15}[/tex] )
= 1 - P( z ≤ 1.4 )
= 1 - 0.9192
= 0.0808 = 8.08 %
⇒P( x ≥ 92 ) = 8.08%
∴ we get
Diana score is > 91.92% other students in the class.
In Micheal case :
Score = 688
Mean score , μ = 493
Standard deviation σ = 150
So,
P( x ≥ 688 ) = 1 - P( x ≤ 688 )
= 1 - P(z ≤ [tex]\frac{x - u}{\sigma}[/tex] )
= 1 - P( z ≤ [tex]\frac{688 - 493 }{150}[/tex] )
= 1 - P( z ≤ 1.3 )
= 1 - 0.9032
= 0.0968 = 9.68 %
⇒P( x ≥ 688 ) = 9.68%
∴ we get
Micheal score is > 90.32% other students in the class.
From both scores , we can conclude that
Diana's score is better.
Miranda needs to add 68+19 mentally but is struggling.If she knows that 68+20=88 how can she use this to help.Use a similar approach to describe how Miranda could add 37+29 mentally
find the perimeter n area pls !
Answer:
6yx
Step-by-step explanation:
Josh has 4 boxes of candy to share with his 20 classmates. If each classmate receives the same amount of candy, how much candy should each classmate get? Your answer
Answer:
1/5 of a box of candy
Step-by-step explanation:
Because John has 4 boxes of candy, he needs to divide this by his 20 classmates. So we have 4/20, which reduces to 1/5. So each classmate would get 1/5 of a box of candy (assuming that Josh himself does not get any candy).
Select the equation that contains the point (4,7) and in which the slope equals 1
Answer:
y-7=x-4
Step-by-step explanation:
If you change the equation to y=mx+b yout would get Y=x+3 plug in the point (4,7) and you would get 7=4+3
7=7 so that is correct.
Will give brainliest
Answer:
A and D
Step-by-step explanation:
Answer:
A and D.
Step-by-step explanation:
The main property of rhombi is that they have all four congruent sides.
So the only two quadrilaterals with four congruent sides are A and D.
what is the distance between -14 and 36 feet
Answer:
Your awnser is 50
Step-by-step explanation:
Have a great day! :D
Answer:
50
Step-by-step explanation:
because if you look on a line graph -14 then it takes 14 feet to get it to 0 then 36 more to get it even with 36 then add 14 and 36 and u get 50
evaluate 9.3s+8.9t when s=3 and t=4
Answer:
63.5
Step-by-step explanation:
9.3(3)+8.9(4) = 63.5
substitute the values (s and t) with the given numbers (3 and 4.)
Answer:
63.5
Step-by-step explanation:
Cuanto es 1+2:
pOrFa NoSe
Answer:
3
Step-by-step explanation:
es hora de comer
The sum of two numbers is 50. One number is 28 more than the other. Find the numbers.
Answer:
Step-by-step explanation:
28+22 is 50
Answer:
12+28=50
Step-by-step explanation:
hi can you guys help me with this :)
Answer:
1/2 + 1/4 would be 3/4.
1/2 + 1/6 would be 2/3.
Step-by-step explanation:
Answer:
No 2 :8
Sorry if wrong........
What is the answer??????????????????????
Answer:
I think so Yes
Step-by-step explanation:
find the prime facrorization for 100 A.2² × 5² B.2×50 C.4×25 D.2³ × 5² E. 2² × 5³
Answer:
A
Step-by-step explanation:
100-25*4=5 squared*2 sqaured
so A
Answer:
prime factorization of 100=a.2²+5²
To order a pizza, you must choose a type of crust, a type of sauce, and also a size. How could you determine the number of outcomes?
# of different crust choices x # of different sauces x # of different sizes = the # of outcomes u'll end up w :)
Answer:abe
Step-by-step explanation:
HELP FAST PLS ILL LOVE U FOREVER <3 Angle ABC is 47 degrees. What is the the measure of angle CBD?
Answer:
43
Step-by-step explanation:
we know that ABC and CBD need to add up to 90 so we have
47+CBD=90
CBD=43
Answer:43Step-by-step explanation: if angle ABD is 90 degrees, and abc+cbd=ABD then ABD-ABC=CBD 90-47=CBD which is 43
Write the equation in standard form.
y = 7x + 2/3
Answer:
It is probably 21x-3y= -2
Answer:
Here is the ANSWEr :p
Step-by-step explanation:
Sorry it dark my time is 7:37pm Wed Feb 24 2021!!!!
IN FACTORED FORM PLZ!!
DUE TONIGHT HELP!!! WILL MARK THE BRAINLIEST!!
Answer:
Step-by-step explanation:
y=(2x+3)^2(x-5)
The difference of two numbers is 2. Their sum is 12. What are the numbers?
Answer:
the numbers would be 5 and 7.
Step-by-step explanation:
"the difference of two numbers is 2."
7 - 5 = 2"their sum is 12."
7 + 5 = 12since the difference of 7 and 5 is 2 and the sum of 7 and 5 is 12, 5 and 7 are the numbers that fulfill the statement.
i hope this helps! have a lovely rest of your day <3
18. Jackie drives 160 miles from Gary, Indiana to
Indianapolis, Indiana in 4.5 hours. At that rate,
how long would it take her to drive from Gary to
Detroit, Michigan, which is a distance of 240
miles?
Answer:
11 hours and 15 minutes (11.25)
Step-by-step explanation:
make a ratio
160:4.5
240/160=1.5
so 1 and 1/2 intervals of 4.5 hours
4.5+4.5= 9
4.5/2=2.25
9+2.25=11.25
The solution is 3.75 hours
The time taken by Jackie to drive a distance of 240 miles is given by the equation A = 3.75 hours
What is Speed?Speed is defined as the rate of change of position of an object in any direction. Speed is measured as the ratio of distance to the time in which the distance was covered. Speed is a scalar quantity as it has only direction and no magnitude
Speed = Distance / Time
Given data ,
Let the equation be represented as A
Now , the value of A is
Jackie drives 160 miles from Gary, Indiana to Indianapolis, Indiana in 2.5 hours
Distance = 160 miles
Time = 2.5 hours
So , the speed = distance / time
Substituting the values in the equation , we get
Speed = 160 / 2.5
Speed = 64 miles / hour
Now , the new distance = 240 miles
So , the Time required = Distance / Speed
Substituting the values in the equation , we get
Time required A = 240 / 64
Time required A = 3.75 hours
Therefore , the value of A is 3.75 hours
Hence , the time taken with a speed of 64 mph is 3.75 hours
To learn more about speed click :
https://brainly.com/question/22228723
#SPJ2
PLEASE HELP I WILL GIVE BRAINLIEST!!!!!!!!!!!
Abby was decorating her room. She arranged 56 picture tiles on a wall in the shape of a rectangle. How many rows of tiles could she have on the wall?
Answer:
14
Step-by-step explanation:
A rectangle has four sides so all you have to do is 56÷4
Answer:
14
Step-by-step explanation:
I was Slightly confused But with the given information
Divide 56 and 4...
Which of these is part of the solution for x > -5?
A
-15
B
-6
C
-5
D
5
Answer:
d
Step-by-step explanation:
because its reverse for negative the lower the better or in this case 5 because its on the other side of 0
Answer:
D. 5
Step-by-step explanation:
I SUCK AT THIS. PLEASE HELP! Factor x^2-11x+24x.
Answer: I think it is (x+3) (x+8)
[tex]x^{2} +13[/tex]
Step-by-step explanation: can u gimme brain plz!
Choose the angle that is supplementary to angle 2. (it's not angle 3 btw)
Answer:
Angle 1
Step-by-step explanation:
Supplementary = Two angles that has a sum of 180 degrees
Angle 1 + Angle 2 = 180 degrees
Simplify: 10 divided by 1/4
1) 40
2) 1/40
3) 2 and 1/2
4) 20
Answer:
1
Step-by-step explanation:
10*4=40
so 1
Find the equation of the line with slope –5/2
and y-intercept (0,0).
Answer:
y= -5/2X
.....................
Find mZB in the parallelogram.
B
С
51°
A
D
7
mZB=
Answer:
plzz show me the diagram otherwise I can't help you sorry!!!!
life is slavery
all your life you work
first its preschool
then its school
then college
then you go off to work
then you retire and rot away in your kids' house or in a retirement home
then you die
one day you are a 13 year old rocking out to nirvana then you die
i don't know how to feel about this but this is deep
bro- are you ok? like really- are you good?
How did you even get 10?
A
10 for what? is there a problem? I could help solve it
Step-by-step explanation: