Plz help 7th grade math ASAP

Using the frequency table given, find the mean, median, and mode.

aalyn [17]

Answer:

$Mean = 69$

$Mode = 66$

$Median = 69$

Step-by-step explanation:

Given

The frequency table

Required

Determine the mean, median and mode

Calculating Mean

$Mean = \frac{\sum fx}{\sum f}$

Where

fx = product of frequency and inches

f = frequency

So;

$Mean = \frac{63 * 2 + 65 * 1 + 66 * 4 + 67 * 3 + 68 * 1 + 69 * 2 + 70 * 2 + 71 * 1 + 72 * 3 + 74 * 2 + 75 * 2}{2 + 1 + 4 + 3 + 1 + 2 + 2 + 1 + 3 + 2 + 2}$

$Mean = \frac{1587}{23}$

$Mean = 69$

Calculating Mode

$Mode = 66$

Because it highest frequency of 4

Calculating Median

$Median = \frac{\sum f}{2}th\ position$

$Median = \frac{2 + 1 + 4 + 3 + 1 + 2 + 2 + 1 + 3 + 2 + 2}{2}th\ position$

$Median = \frac{23}{2}th\ position$

$Median = 11.5th\ position$

Approximate

$Median = 12th\ position$

At this point we, need to get the cumulative frequency (CF)

Inches ---- Frequency ---- CF

63 -------------2------------------2

65 -------------1------------------3

66 -------------4------------------7

67 -------------3------------------10

68 -------------1------------------11

69 -------------2------------------13

70 -------------2------------------15

71 -------------1------------------16

72 -------------3------------------19

74 -------------2------------------21

75 -------------2------------------23

From the above table

Since the median fall in the 12th position, then we consider the following data

69 -------------2------------------13

because it has a CF greater than 12

Hence;

$Median = 69$

7 0

4 years ago

A random sample produced the pie chart below. The chart gives percentages of students that under reported, accurately reported,

tiny-mole [99]

Answer:

The correct option is A.

Step-by-step explanation:

Total number of students at the school is 2,500.

In the given pi chart Pink, Yellow and Sky Blue color represent the percentage of students that under reported, accurately reported, and over reported their heights respectively.

From the graph we can conclude that the yellow portion is approximately one fifth of whole circle. It means the number of students that accurately reported their height is one fifth of total number of students.

$2500\times \frac{1}{5}=500$

Therefore the number of students that accurately reported their height is 500. Option A is correct.

7 0

3 years ago

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Solve. 8/5 = -15- 7z/30

xxTIMURxx [149]

Answer:

-138/7

Step-by-step explanation:

use l.c.m . Or multiply through by 30.

3 0

3 years ago

Please help me . I need help with this. I’m getting very very frustrated !!! You can get 35 points !

Elden [556K]

Notes:

The sign of the coefficient of the quadratic equation determines if the vertex is a minimum or maximum. Positive looks like ∪ so has a minimum. Negative looks like ∩ so has a maximum.
Maximum/minimum height is the y-value of the vertex.
Time to reach maximum height is the x-value of the vertex (which is also the Axis-Of-Symmetry).

Answer: 4) maximum

5) 20.1 ft

6) 2 seconds

Step-by-step explanation:

4) h(t) = -16t² + 256t

↓

the coefficient is negative so it looks like ∩.

Therefore, it has a maximum.

5) h(t) = -16t² + 30t + 6

$\text{AOS: }x=\dfrac{-b}{2a}\quad \rightarrow \quad x=\dfrac{-(30)}{2(-16)}=\dfrac{-30}{-32}=\dfrac{15}{16}\\\\\\\text{Maximum: }h\bigg(\dfrac{15}{16}\bigg)=-16\bigg(\dfrac{15}{16}\bigg)^2+30\bigg(\dfrac{15}{16}\bigg)+6\\\\\\.\qquad \qquad \qquad \qquad =\dfrac{-225}{16}+\dfrac{450}{16}+\dfrac{96}{16}\\\\\\.\qquad \qquad \qquad \qquad =\dfrac{321}{16}\\\\\\.\qquad \qquad \qquad \qquad \approx20.1$

6) h(t)=-16t²+64t+80

$\text{AOS: }x=\dfrac{-b}{2a}\quad \rightarrow \quad x=\dfrac{-(64)}{2(-16)}=\dfrac{-64}{-32}=2$

8 0

3 years ago

7 pairs of stockings cost as much as 3 T-shirts, and a trousers as much as 1 T-shirt and 2 pairs of stockings. How many trousers

netineya [11]

Answer:

number of trousers=14

numbers of pairs of stockings=71

Step-by-step explanation:

Pairs of stockings: x

T shirt: y

Trouseres: z

7x=3y

1z=1y+2×

__________________________________________

m: number of trousers

m*z=26y

m*(y+2x)=26y

m*(y+2(3y/7))=26y

m=26y/(y+2(3y/7))

m=14

You need to buy 14 trousers that represents the equivalent of 26 T-shirts.

__________________________________________

k:pairs of stockings

k*x=10y+11z

k*x=10(7x/3)+11(y+2x)

k*x=10(7x/3)+11((7x/3)+2x)

k=71

You need to buy 71 pairs of stockings with an amount equal to the price of 10 T-shirts and 11 trousers

3 0

2 years ago

Read 2 more answers