Answer:
12
Step-by-step explanation:
(# of pencils)x(3/4)=9
(# of pencils)x(0.75)=9
(# of pencils)=9/(0.75)=12
Answer:
-9
Step-by-step explanation:
The awnswer to the first equation is -4 and -4-5 is equal to -9
Answer: 
Step-by-step explanation:
You know that the triangle ABC and the triangle DEF are similar.
Therefore, if the lenght of AC is 12 centimeters and the lenght of DF is 10 centimeters, then you can find the ratio as following:
Then, the calculte the length of EF, you must multiply the lenght BC of the triangle ABC by the ratio obtained above.
Therefore, the lenght EF is the following:
1) Call x the sample mean = 3.56
2) Call s the sample standard deviation = 0.2
3) Given that the variable is normally distributed and the sample is large, you determine the interval of confidence from:
x +/- Z(0.5) s/√n
Wehre Z(0.5) is the value of the probabilities over 5% (90% of confidence mean to subtract 10%, which is 5% for each side (tails) of the normal distribuition) and is taken from tables.
Z(0.5) = 0.3085
Then the inteval is
x +/- 0.385 *s /√n = 3.56 +/- 0.385 * 0.2/√45
3.56 +/- 0.011 = ( 3.549, 3.571). This is the answer.
