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:
mean is 5
Step-by-step explanation:
<h2>
MEAN</h2>
mean is regarded as the average number of items
<h3>mean formula:</h3>
<em>(sum of terms) / (number of terms)</em>
<h3><u /></h3><h3><u>Firstly</u></h3>
the numbers in the data set are :
3,3,3,4,6,6,7,8
they are already arranged in order, so no need to rearrange.
<h3><u>Next </u></h3>
add the numbers together to find the total :
3 +3 +3 +4 +6+ 6+7 +8
= 40
ALSO,
find how many number of terms they are --- this is 8
Last
use the mean formula to solve :
<em>(sum of terms) / (number of terms)</em>
= 40/8
= 5
<h3><em>
<u>the mean is the 5 </u></em></h3>
Think of the 13-ft length of the ladder as the hypotenuse of a right triangle. Represent the horiz. distance from foot of ladder to base of tree by x, or 5 ft.
Represent the vert. dist. from base of tree to top of ladder by y, which is unknown.
Then (13 ft)^2 = (5 ft)^2 + y^2, or
169 ft^2 = 25 ft^2 + y^2. This simplifies to y^2 = 144. Thus y = + 12 feeet.
Note: Please pay attention to your spelling: "lader i up agenst a tree" should be "the top of a 13-ft ladder is placed against a tree."
Answer:
d=32!!!
Step-by-step explanation:
So first rewrite it as an equation: d/4+12=20
d/4+12=20 then subtract 12 from both sides to balance the equation
d/4=8 so multply both sides by 4 to isolate the variable, 4(d/4)=d =d and 8x4=32, so d=32
Answer:
Step-by-step explanation:
Semester Costs = 8*2858 = 22864
Books / semester= 8 * 391 = <u>3128</u>
Total 25992
If he wants to repay all this in six years the answer would be
45000 + 25992/6 = 45000 + 4332 = 49332
