Answer:
Refer to the attachment and Thank U
A standard deviation is 2500 miles, so the range of 25,000 to 37,500 is 2 standard deviations below, and 3 standard deviation above the mean of 30,000.
We aren't assuming anything about the distribution, but we sort of have to assume a normal distribution in order to answer. When you don't know anything about a distribution, this is generally what you do.
The general rule for standard deviations is:
+/- 1 SD: +/- 34% of population, for a total of 68%
+/- 2 SD: Another 14% in either direction, for a total of 96% of population.
+/- 3 SD, Another 2% in either direction, which pretty much captures the entire distribution (4 standard deviations from the mean is incredibly rare/unlikely)
We have a range of +/- 1 SD, so we know that 68% percent o the tire 'population' is captured in the range. We also have one more standard deviation in both directions, so we add 28% to this number to get 96% of the population. We have a third standard deviation above the mean, so we add another 2% to arrive at 98% of the population.
Answer is 98% of all such tires.
Answer:
x = amount of pure acid to be added = 6.67ml
Step-by-step explanation:
George wishes to increase the percent of acid in 50ml of a 15% acid solution in water to 25% acid, how much pure acid must you add?
let
x = amount of pure acid to be added
15% of 50 + x = 25% of 50 + x
(0.15 * 50) + x = 0.25(50 + x)
7.5 + x = 12.5 + 0.25x
Collect like terms
x - 0.25x = 12.5 - 7.5
0.75x = 5
x = 5/0.75
x = 6.6666666666666
Approximately,
x = 6.67
x = amount of pure acid to be added = 6.67ml
Answer : (3,-1) Hoped this helped :)
Answer:
positive
Step-by-step explanation:
If the variables tend to increase and decrease together, the association is positive.
hope this helps :)
