By assuming the standard deviation of population 2.2 the confidence interval is 8.67 toys,8.94 toys.
Given sample size of 1492 children,99% confidence interval , sample mean of 8.8, population standard deviation=2.2.
This type of problems can be solved through z test and in z test we have to first find the z score and then p value from normal distribution table.
First we have to find the value of α which can be calculated as under:
α=(1-0.99)/2=0.005
p=1-0.005=0.995
corresponding z value will be 2.575 for p=0.995 .
Margin of error=z*x/d
where x is mean and d is standard deviation.
M=2.575*2.2/
=0.14
So the lower value will be x-M
=8.8-0.14
=8.66
=8.67 ( after rounding)
The upper value will be x+M
=8.8+0.14
=8.94
Hence the confidence interval will be 8.67 toys and 8.94 toys.
Learn more about z test at brainly.com/question/14453510
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Thirty-two thousand six hundred fifty-one
Answer: D) Number of yards Jerry cuts; 0 ≤ x ≤ 10
Step-by-step explanation:
Here the given function that describes the total profit,
y = 15 x - 10
Where x represents the number of lawns Jerry cut in a week.
But, Depending homework and chores, he has time to cut at most 10 lawns a week.
Thus, x ≤ 10
Also, the number of lawns can not be negative.
Therefore, x ≥ 0
And, the value of x will decide the domain of the function y,
Thus, the domain of the given function is,
0 ≤ x ≤ 10
⇒ Option D is correct.
Answer:
y = -x + 4
Step-by-step explanation:
(-1,5)...x1 = -1 and y1 = 5
(1,3)....x2 = 1 and y2 = 3
slope(m) = (y2 - y1) / (x2 - x1) = (3 - 5) / (1 - (-1) = -2 / (1 + 1) = -2/2 = -1
y = mx + b
slope(m) = -1
u can use either of ur points...I will use (1,3)...x = 1 and y = 3
now we sub and find b, the y int
3 = -1(1) + b
3 = -1 + b
3 + 1 = b
4 = b
ur equation is : y = -x + 4 <===
7x+(x-4)(X+5)-5x
7x+(X*2+ 5x-4x-20)-5x
7x+(X*2+ x-20)-5x
X*2+3x-20
