Answer:
a)
90% confidence interval for the mean grading time of all composition papers.
(12.47981 , 13.52019)
b)
Appropriate inequality
The interval is ( 12.47981 < μ < 13.52019)
Step-by-step explanation:
<u><em>Explanation</em></u>:-
a)
Given sample size 'n' = 40
Mean of the sample = 13 minutes
standard deviation = 2 min
level of significance = 0.10 or 90%
90% confidence interval for the mean grading time of all composition papers.
( 13 - 0.52019 , 13 + 0.52019)
(12.47981 , 13.52019)
b)
The interval is ( 12.47981 < μ < 13.52019)
Answer:
a. 17.80 b. 71.20
Step-by-step explanation:
I used to hate percents. Let me teach you a trick:
take the og value (89) and multiply it by the percentage (20% or 0.2). Then once you have that answer (17.80), subtract it from the og value (89-17.80). That's your answer for how much you still owe! (71.20)
any other follow up questions? Just ask :)
Answer:
y = 2x+1 (slope-intercept form)
Step-by-step explanation:
From line B, y = 2x -2 and comparing with the general equation of line, y = mx +c, we have
m1 = 2
Parallelism rule states that m1=m2
Therefore, m2 = 2
Hence, the equation passing through point A(1,3) is
y-y1 = m2(x-X1)
y - 3 = 2(x-1)
y-3 = 2x-2
y = 2x-2+3
y = 2x+1 (slope-intercept form)
For perpendicular lines, m1m2 = -1 or m2 = -1/m1; where m1 and m2 are the slopes of the lines.
Here line 1 is 2x - y - 7 = 0
y = 2x - 7; Hence m1 = 2
m2 = -1/2
Required equation y - y1 = m2(x - x1)
y - (-1) = -1/2(x - 4)
y + 1 = -1/2x + 2
y = -1/2x + 2 - 1
y = -1/2x + 1
Working:
$5.29 + ((2/3) x 3.59) + ((4/3) x 4.79)
= $14.07 (to 2d.p.)
So, she estimated correctly that she will spend around $14 on the flowers but slightly more than $14, so I don't really know if you should say that she estimated correctly or not
