To solve this problem, we use the formula:
z = (x – u) / s
where z is the z score value which can be obtained from
the tables, x is the sample value, u is the mean = 6.3 min, and s is the std
dev = 2.2 min
at P value = 0.90, the z = 1.28, finding for x:
x = z s + u
x = 1.28 * 2.2 + 6.3
x = 9.116
at P value = 1.0, the z = 3.49, finding for x:
x = z s + u
x = 3.49 * 2.2 + 6.3
x = 13.978 ~ 14
Therefore the longest 10% calls last about 9.1 minutes to
14 minutes
Answer:
78 nickels and 22 dimes
Step-by-step explanation:
Nickels = n, Dimes = d
<u>Number of coins = 100</u>
<u>Total sum in the piggy bank = $6.60 </u>
<u>Consider the first equation in the second:</u>
- 5(100 -d) + 10d = 660
- 500 - 5d + 10d = 660
- 5d = 110
- d = 110/5
- d = 22
- n = 100 - 22
- n = 78
<u>Answer:</u> nickels 78 and dimes 22
Answer:
C
Step-by-step explanation:
Hose A:
60 gallons every 15 minutes mean:
60 / 15 = 4 gallons per minute
For Hose B:
If we put x = 1, we can find gallons (y) per minute (x)
y = 3 x
y = 3(1)
y = 3
That means 3 gallons per minute
Thus, the rate of Hose A is 1 gallon per minute more than the rate of Hose B. Option C is correct.
4.2 hours x .4 gallons per hour = 1.68 gallons
