Answer:
c. (12.12, 18.48)
Step-by-step explanation:
Hello!
The study variable is X: number of times a racehorse is raced during its career.
The average number is X[bar]= 15.3 and the standard deviation is S= 6.8 obtained from a sample of n=20 horses.
To estimate the population mean you need that the variable has a normal distribution, in this case, we have no information about its distribution so I'll assume that it has a normal distribution. With n=20 the most accurate statistic to use for the estimation is a Students-t for one sample, the formula for the interval is:
X[bar] ± 

[15.3 ± 2.093 *
]
[12.12; 18.48]
Using a significance level of 95% you'd expect that the true average of times racehorses are raced during their career is included in the interval [12.12; 18.48].
I hope it helps!
Answer:
a. 10
b. 0.1
Step-by-step explanation:
a. The t-shirts comes in 5 sizes (Small,medium,large, extra large and extra extra large) and two colors orange and black. The total different type of shirts are 5*2=10 different type of t-shirts.Also if we make sample space of all shirts we can assess the total different type of t-shirts. sample space=S={small orange,medium orange,large orange,XL orange,XXL orange,small black,medium black,large black,XL black,XXL black}. n(S)=total different type of shirts=10.
b. P( large orange t-shirt)=n(large orange t-shirt)/n(S)=1/10=0.10.
times more stars are there in universe compared to human eye can see
<h3><u>
Solution:</u></h3>
Given that, conservative estimate of the number of stars in the universe is 
The average human can see about 3,000 stars at night with only their eyes
To find: Number of times more stars are there in the universe, compared to the stars a human can see
Let "x" be the number of times more stars are there in the universe, compared to the stars a human can see
Then from given statement,

<em><u>Substituting given values we get,</u></em>

Thus
times more stars are there in universe compared to human eye can see
Answer:
-37/5= y
x=11/5
Step-by-step explanation:
4x-3y=31
-3y=-4x+31 regroup it to match the other
-2 y=(2x-3)(-2) multiply by -2 to get -4x
-3y=-4x+31
-2y=-4x+6 adding
-5y=37 divide
-37/5= y
4x-3(-37/5)=31
x=11/5
7.67 is your answer. hope this helps, let me know if you need more help