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Neporo4naja [7]

3 years ago

7

428 students were surveyed about their preferences of sports. 133 students like football, 142 students like baseball, and 50 stu

dents like both sports. How many students like exactly one of the two sports

1 answer:

trasher [3.6K]3 years ago

4 0

Answer:

Step-by-step explanation:

You might be interested in

The ages of max and his father add up to 35 years. Max's father's age is the same as five more than the square of max's age

34kurt

M+f=35
f=5+m^2
sub 5+m^2 for f
m+5+m^2=35
m^2+m+5=35
minus 35 both sides
m^2+m-30=0
factor
what 2 numbers mulitply to get -30 and add to get 1
-5 and 6
(m-5)(m+6)=0
set to zto
m-5=0
m=5

m+6=0
m=-6
age can't be negative

max is 5
father is 30

5 0

3 years ago

tatyana61 [14]

Answer:

I would say A but I might be wrong, I'm not to clear on this. But I hope it helps

Step-by-step explanation:

8 0

3 years ago

Whag is an equivalent fraction for 3/8

BabaBlast [244]

The fraction for that is 1/2

7 0

3 years ago

Read 2 more answers

Do bonds reduce the overall risk of an investment portfolio? Let x be a random variable representing annual percent return for V

ryzh [129]

Answer:

a.

∑x=109, ∑x²=4173, ∑y=87, ∑y²=2083.

b.

sample mean for x=10.9.

variance for x=331.66.

standard deviation for x=18.21.

sample mean for y=8.7.

variance for y=147.34.

standard deviation for y=12.14.

c.

75% Chebyshev interval around the mean for x values

-25.52,47.32

75% Chebyshev interval around the mean for y values

-15.58,32.98

The interval shows that Vanguard Balanced index has smaller spread.

d.

coefficient of variation for x=167.06%

coefficient of variation for y=139.54%

Smaller CV means lower risk so, smaller CV is better.

Step-by-step explanation:

Note: ALL ANSWERS ARE ROUNDED TO TWO DECIMAL PLACES

a.

∑x=17+0+17+28+28+27+29−12−12−13=109,

∑x²=17²+0²+17²+28²+28²+27²+29²+(−12)²+(−12)²+(−13)²=4173,

∑y=14−2+27+18+20+11+14−2−3−10=87,

∑y²=14²+(−2)²+(27)²+(18)²+(20)²+(11)²+(14)²(−2)²+(−3)²+(−10)²=2083.

b.

sample mean for x=∑x/n=109/10=10.9.

$variance x=\frac{sum(x-mean )^2}{n-1}$

x-mean

6.10

-10.90

6.10

17.10

17.10

16.10

18.10

-22.90

-22.90

-23.90

sum(x-mean)²=6.10 ²+(-10.90 )²+6.10 ²+17.10² +17.10²+ 16.10² +18.10² +(-22.90 )²+(-22.90 )²+(-23.90 )²=2984.9

$variance x=\frac{2984.9}{9}$

Variance for x=331.66.

standard deviation for x=√variance for x

standard deviation for x=√331.66

standard deviation for x=18.21.

sample mean for y=∑y/n=87/10=8.7.

$variance y=\frac{sum(y-mean )^2}{n-1}$

y-mean

5.30

-10.70

18.30

9.30

11.30

2.30

5.30

-10.70

-11.70

-18.70

sum(y-mean)²=5.30 ²+(-10.70 )²+18.30² +9.30² +11.30² +2.30² +5.30² +(-10.70 )²+(-11.70 )²+(-18.70 )²=1326.1

$variance y=\frac{1326.1}{9}$

variance for y=147.34.

standard deviation for y=√variance for y

standard deviation for y=√147.34

standard deviation for y=12.14.

c.

75% Chebyshev Interval

mean±k standard deviation

We have to find value of k.

$1-\frac{1}{k^{2} } =0.75$

$1-0.75 =\frac{1}{k^{2} }$

$\frac{1}{k^{2} }=0.25$

k²=4

k=2

so, 75% Chebyshev Interval for x

10.9±2*(18.21)

[-25.52,47.32]

75% Chebyshev Interval for y

8.7±2*(12.14)

[-15.58,32.98]

The interval shows that Vanguard Balanced index has smaller spread.

d.

$CV for x=\frac{S.Dx}{meanx} *100$

$CV for x=\frac{18.21}{10.9} *100$

CV for x=167.06%

CV for y

$CV for y=\frac{S.Dy}{meany} *100$

$CV for y=\frac{12.14}{8.7} *100$

Cv for y=139.54%

The smaller CV shows the smaller amount of risk so, smaller CV is better.

4 0

3 years ago

(w-7)(w+3) simplified

daser333 [38]

Answer:

$w^{2}$ -4w-21

Step-by-step explanation:

5 0

3 years ago