Answer:
B. Side <em>a</em> is 7 inches long and side <em>b</em> is 6 inches long.
Step-by-step explanation:
Since the scale drawing is three times bigger than the actual object, divide both numbers by three to find the object size.
Side a:
21/3 = 7 inches
Side b:
18/3 = 6 inches
<BAC = <DEC = 30°
<BCA = <DCE = 70°
<CDE (or m<D) = 180° - <DEC - <DCE
<CDE = 180° - 30° - 70°
<CDE = 80°
The number that belongs in the green box is 80
200 yards bozo yeejrkrjrjthbthttjtjtnrm
95% of red lights last between 2.5 and 3.5 minutes.
<u>Step-by-step explanation:</u>
In this case,
- The mean M is 3 and
- The standard deviation SD is given as 0.25
Assume the bell shaped graph of normal distribution,
The center of the graph is mean which is 3 minutes.
We move one space to the right side of mean ⇒ M + SD
⇒ 3+0.25 = 3.25 minutes.
Again we move one more space to the right of mean ⇒ M + 2SD
⇒ 3 + (0.25×2) = 3.5 minutes.
Similarly,
Move one space to the left side of mean ⇒ M - SD
⇒ 3-0.25 = 2.75 minutes.
Again we move one more space to the left of mean ⇒ M - 2SD
⇒ 3 - (0.25×2) =2.5 minutes.
The questions asks to approximately what percent of red lights last between 2.5 and 3.5 minutes.
Notice 2.5 and 3.5 fall within 2 standard deviations, and that 95% of the data is within 2 standard deviations. (Refer to bell-shaped graph)
Therefore, the percent of red lights that last between 2.5 and 3.5 minutes is 95%
