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2 years ago

A bus company recorded the ages, in years, of the people on coach A and the people

Mathematics

1 answer:

xxTIMURxx [149]2 years ago

4 0

Answer:

Median : 59

Lower quartile : 53

Upper quartile : 66

Least age: 41

Greatest age: 79

Step-by-step explanation:

In a ordered list, the median is the number at the half position. With 23 numbers, the half position the 12th number (there are 11 number above and blow it)

41 42 44 48 52 53 53 53 56 57 57 59 60 61 63 64 64 66 67 69 74 77 79

The lower quartile is the number at the half position, only considering the first data points until the median.

41 42 44 48 52 53 53 53 56 57 57

The upper quartile is the number at the half position, only considering the data points after the median.

60 61 63 64 64 66 67 69 74 77 79

The least and greatest ages are easily found.

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Jack is building a square garden. Each side length measures 777 meters. Jack multiplies 7\times77×77, times, 7 to find the amoun

Inessa [10]

Answer:

49 square meters represent area of the square garden

Step-by-step explanation:

Each side length=7 meters

He multiplied 7 × 7 times to find the amount of space

=49 square meters

Jack is trying to measure the area of his square garden

Area of the square garden = length^2

=Length × length

Recall,

Length=7 meters

Area of the square garden= 7 meters × 7 meters

=49 square meters

5 0

2 years ago

Suppose that the IQs of universityâ€‹ A's students can be described by a normal model with mean 140 and standard deviation 8 poi

AnnZ [28]

Answer:

0.0266, 0.9997,0.7856

Step-by-step explanation:

Given that the IQs of universityâ€‹ A's students can be described by a normal model with mean 140 and standard deviation 8 points. Also suppose that IQs of students from university B can be described by a normal model with mean 120 and standard deviation 11. Let x be the score by A students and Y the score of B.

A) $P(X>135) = \\P(Z>0.625)\\=0.0266$

B) Since X and Y are independent we have

X-Y is Normal with mean = 140-120 =20 and $Var (x-y)=Var(x)+Var(y) = 19$

$P(X-Y)>5\\\\=1-0.00029\\=0.9997$

C) For a group of 3, average has std deviation = $\frac{11}{\sqrt{3} } \\=6.351$

$P(\bar y >115)\\= P(z>\frac{-5}{6.351} \\=0.7856$

3 0

2 years ago

Heidi solved the equation 3(x + 4) + 2 = 2 + 5(x – 4). Her steps are below: 3x + 12 + 2 = 2 + 5x – 20 3x + 14 = 5x – 18 14 = 2x

konstantin123 [22]

First, she distributed $3*x=3x , 3*4=12, 5*x= 5x, 5* -4= -20$
Which gave her $3x+12+2=2+5x-20$
Then, she combined like terms $12+2=14 and 2+ -20 = -18$
Which gave her $3x+14=5x-18$
Then, she subtracted $3x$ from both sided
Which gave her $14=2x-18$
Then, she added $18$ to both sides
Which gave her $32=2x$
And finally sh edivided 32 by 2 and got $16=x$
hope this helps if you have any questions please pm me :)

5 0

2 years ago

Read 2 more answers

A statistics practitioner in a large university is investigating the factors that affect salary of professors. He wondered if ev

Ulleksa [173]

Answer:

Step-by-step explanation:

Hello!

Given the linear regression of Y: "Annual salary" as a function of X: "Mean score on teaching evaluation" of a population of university professors. It is desired to study whether student evaluations are related to salaries.

The population equation line is

E(Y)= β₀ + β₁X

Using the information of a n= 100 sample, the following data was calculated:

R²= 0.23

Coefficient Standard Error

Intercept 25675.5 11393

x 5321 2119

The estimated equation is

^Y= 25675.5 + 5321X

Now if the interest is to test if the teaching evaluation affects the proffesor's annual salary, the hypotheses are:

H₀: β = 0

H₁: β ≠ 0

There are two statistic you can use to make this test, a Student's t or an ANOVA F.

Since you have information about the estimation of β you can calculate the two tailed t test using the formula:

$t= \frac{b - \beta }{\frac{Sb}{\sqrt{n} } }$ ~ $t_{n-2}$

$t= \frac{ 5321 - 0 }{\frac{2119}{\sqrt{100} } }$ = 25.1109

The p-value is two-tailed, and is the probability of getting a value as extreme as the calculated $t_{H_0}$ under the distribution $t_{98}$

p-value < 0.00001

I hope it helps!

3 0

2 years ago

Solve x2 = 12x – 15 by completing the square. Which is the solution set of the equation?

Nady [450]

For this case we have the following polynomial:
$x ^ 2 = 12x - 15
$
The first thing to do is to place the variables on the same side of the equation.
We have then:
$x ^ 2 - 12x = -15
$
We complete the square by adding the term (b / 2) ^ 2 on both sides of the equation.
We have then:
$x ^ 2 - 12x + (-12/2) ^ 2 = -15 + (-12/2) ^ 2
$
Rewriting we have:
$x ^ 2 - 12x + (-6) ^ 2 = -15 + (-6) ^ 2

x ^ 2 - 12x + 36 = -15 + 36
 
(x-6) ^ 2 = 21$
$x-6 =+/- \sqrt{21}$
Therefore, the solutions are:
$x = 6 - \sqrt{21}$
$x = 6 + \sqrt{21}$
Answer:
the solution set of the equation is:
$x = 6 - \sqrt{21}$
$x = 6 + \sqrt{21}$

3 0

2 years ago

Read 2 more answers