Answer:
C. 2.0 < t < 2.5
Step-by-step explanation:
time = distance / speed
The circumference of the lake is given by ...
C = πd = 2π miles ≈ 6.28 miles
Then Johanna's time is ...
(6.28 mi)/(3 mi/h) ≈ 2.09 h
This time is in the interval (2, 2.5), so matches choice C.
___
<em>Alternate solution</em>
If we take pi to be 3, then this boils down to ...
2×3/3 = 2 . . . hours
Pi is on the order of 5% more than 3, so her time will be on the order of 5% more than 2 hours, or just above 2, but not as great as 2.5 hours. This sort of estimating can get you to the correct answer without a calculator.
Answer:
3 and 4
and
2 and 6
Step-by-step explanation:
3×4=12
2×6=12
Answer:
$180
Step-by-step explanation:$10 per hour, so 10 is multiplied by 9
He gets paid 90 Dollars for one day of work so we would multiply that by Two days.
Answer: 8000
Step-by-step explanation:
From the question, we are informed that the expression 10³ × 2^w models the population of the bacteria after w weeks.
The number of bacteria that will be present in 3 weeks will then be:
= 10³ × 2^w
= 10³ × 2³
= 1000 × 8
= 8000 bacterias
Answer:
The expected number of sales of this store from this sample of 30 is 6.
Step-by-step explanation:
For each prospect, there are only two possible outcomes. Either there is a trade, or there is not. Prospects are independent of each other. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The expected value of the binomial distribution is:
A retail variety store that advertises extensively by mail circulars expects a sale with 20% probability.
This means that 
Suppose 30 prospects are randomly selected from a city-wide mailing.
This means that 
What is the expected number (mean) of sales of this store from this sample of 30?
The expected number of sales of this store from this sample of 30 is 6.
