X^2- 6x - 7 = 0 can someone help me solve this by completing the square
2 answers:
You might be interested in
Answer:
Step-by-step explanation:
Hello!
You have the data on 443 rounds of golf played on the 12th hole.
The variable of interest is:
X: score of one round of golf played on the 12th hole.
To construct the empirical distribution of the discrete variable you have to organize the data from least to highest and count how many times each score was recorded, establishing the absolute frequency for each value of the variable.
a. Check attachment.
fi= absolute frequency
Fi= accumulated absolute frequencies
hi= relative frequency
Hi= accumulated relative frequency
b.
P(X≤4)
This is the probability of the player scoring "4 or less", so it includes the probability of the player scoring 3 and the player scoring 4, symbolically:
P(X≤4)= P(X=3)+P(X=4)= H(4)= 0.136
c.
The expected score of a discrete variable is:
E(X)= [∑(Xi*fi)]/n= 2343/443= 5.29
d.
To calculate the variance of the variable you have to use the following formula:
V(X)= 1/(n-1)*[∑(Xi²*fi)-(∑(Xi*fi)²]/n)] = (1/442)*[12831-(2343²/443)]
V(X)= 0.993
e.
The standard deviation is the square root of the variance:
√V(X)=√0.993= 0.994
I hope it helps!
Answer:
5 trees should be planted to maximize the yield per acre,
The maximum yield would be 1250
Step-by-step explanation:
Given,
The original number of trees per acre = 20,
Average pounds of nuts by a tree = 60,
Let x be the times of increment in number of trees,
So, the new number of trees planted per acre = 20 + x
∵ for each additional tree planted per acre, the average yield per tree drops 2 pounds,
So, the new number of pounds of nut = (60 - 2x)
Thus, the total yield per acre,
Differentiating with respect to t ( time ),
Again differentiating with respect to t,
For maxima or minima,
⇒ 20 - 4x = 0
⇒ 20 = 4x
⇒ x = 5,
For x = 5, Y''(x) = negative,
Hence, Y(x) is maximum for x = 5,
And, maximum value of Y(x) = (20+5)(60 - 10) = 25(50) = 1250,
i.e. 5 trees should be planted to maximize the yield per acre,
and the maximum yield would be 1250 pounds