Answer:
Step-by-step explanation:
The formula for determining confidence interval is expressed as
Confidence interval
= mean ± z × s/ √n
Where
z is the value of the z score
s = standard deviation
n = sample size
a) The 95% confidence level has a z value of 1.96
The 99% confidence level has a z value of 2.58
Since 99% confidence level z value is greater than 95% confidence level z value, if we input it into the formula, it will result to a higher confidence interval. So changing from a 95% confidence level to a 99% confidence level would make a confidence interval wider.
b) The √15 is smaller than the √350. This means that if we make use of the formula, √350 will give a lower confidence interval than that of √15. Therefore, the confidence interval would be narrower changing from a sample size of 15 to a sample size of 350.
c) Applying the formula, a standard deviation of 15 pounds would result to a lower confidence interval than a standard deviation of 20 pounds. Therefore, the confidence interval would be wider changing from a standard deviation of 15 pounds to a standard deviation of 20 pounds.
Pretty sure you just add 80% and 20% to get 100%, hope this helps....
Answer: x=-2
Step-by-step explanation: Isolate the variable by dividing each side by factors that don't contain the variable.
Hope this helps you out.
<u>Answer:</u>
<h2>A = 15 u²</h2>
<u>Explanation:</u>
according to the coordinates the triangles is right at the pair (2, -3)
the area of the triangle = height × base × 1/2
the <u>height</u> is the line passing through the pairs (-1, 6) and (2, -3)
h² = (2-(-1))²+(-3-6)²
h² = 3² + (-9)²
h² = 9 + 81
h² = 90
h = √90
the <u>base</u> is the line passing through the pairs (5, -2) and (2, -3)
b² = (2-5)²+(-3-(-2))²
b² = 3² + (-3+2)²
b² = 9 + 1
b² = 10
b = √10
A = h×b×1/2
A = √90×√10×1/2
A = √900×1/2
A = 30×1/2
A = 15 u²
So the fraction would be 23/35 are boys. If you do the division (23 ÷ 35) the answer is around 0.657.
That converted into a percentage (×100) is 65.7%
