Answer: a) 0.84 b) 0.67 c) 1.28
Step-by-step explanation:
Using the standard normal distribution table for z-value , we have
(a) The value of
would result in a 80% one-sided confidence interval : 
(b) The value of
would result in a 85% one-sided confidence interval : 
(c) The value of
would result in a 90% one-sided confidence interval : 
2.8 = 2 + 0.8
*let's analyze the decimal 0.8 as a fraction
0.8 = 8/10
*but if we divide the numerator and denominator by the same common factor of 2, we find that the fraction can be reduced to:
(8/2)/(10/2) = (4)/(5) = 4/5
*now evaluating the whole value of 2 (from the 2.8), we know there are a total of (5) - fifths in order to make a whole, so for 2 whole, we require:
2*(5/5) = (2*5)/5 = 10/5
*Now we add the fractions together:
2 = 10/5
0.8 = 4/5
10/5 + 4/5
*add numerators only, the denominator stays as a 5
(10 + 4)/5 = 14/5
*there are no common factors between 14 & 5 (other than 1, but that won't help reduce the fraction any), so the fraction is in it's simplest form:
answer is: 14/5
Answer:
2.5
Step-by-step explanation:
From the diagram, figure B was enlarged to obtain figure A.
The two figures are therefore similar.
The corresponding sides are in the same proportion. That constant value of the proportion is called scale factor.
It is given by:

Figure B is the image of A

Therefore the scale factor is 2.5
In triangle ABC,
AC = 12/ (sin30) = 12 / (1/2) = 24
DC = 24-x
DB = DC tan 30 = (24-x) tan30 <span>=(24−x)/</span><span>√3
</span>
In triangle ADB using Pythagorean Theorem<span><span>x2</span>+((24−x)/<span>√3</span><span>)2</span>=<span>12^2</span></span><span><span>x2</span>+(24−x<span>)^2</span>/3=<span>12^2</span></span><span>3<span>x2</span>+(24−x<span>)^2</span>=432</span><span>4<span>x2</span>−48x+576=432</span><span>4<span>x2</span>−48x+144=0</span><span><span><span>x2</span>−12x+36=0
x1 = x2 =6
AD = AC - DC = 24- (24-x) = 6</span></span>