Answer:
sales tax is $3.50.
She would have to pay $73.50
Step-by-step explanation:
5% of 70 is 3.5 (sales tax)
70+3.5= 73.5
Answer:
What percentage of pick-up truck drivers want their next vehicle purchase to be another pick-up truck?
Should the speed limit be decreased on the highway connecting two large cities?
How many pedestrians would use a walkway built over a busy road?
Step-by-step explanation:
We use samples when using an entire population is not feasible.
It is not reasonable to ask every pick-up truck driver what they want their next purchase to be; there are too many owners of pick-up trucks. This means we should use a sample.
Many people drive a highway that connects two large cities. It is not reasonable to survey every person that drives it, so we should use a sample.
On a busy road, we may have many pedestrians; this means we should use a sample instead of the entire population.
Answer:
0.9999
Step-by-step explanation:
Let X be the random variable that measures the time that a switch will survive.
If X has an exponential distribution with an average life β=44, then the probability that a switch will survive less than n years is given by
So, the probability that a switch fails in the first year is
Now we have 100 of these switches installed in different systems, and let Y be the random variable that measures the the probability that exactly k switches will fail in the first year.
Y can be modeled with a binomial distribution where the probability of “success” (failure of a switch) equals 0.0225 and
where
equals combinations of 100 taken k at a time.
The probability that at most 15 fail during the first year is