Answer:
The probability distribution of the number of customers that enter the store on a given day is:
Step-by-step explanation:
To calculate a parameter for the given day, we have to calculate what is the average arrival rate for the day.
This can be done with the data given:
1) From 10 to 12, 8 arrival/hour: 16 expected arrivals in this period
2) From 12 to 2, 8 to 12 arrival/hour (average: 10 arrivals): 20 expected arrivals in this period.
3) From 2 to 5, from 10 to 4 arrival/hour (average: 7 arrivals): 21 expected arrivals in this period.
The total expected arrivals in a day are: 16+20+21=57 arrivals/day.
Then, the probability distribution of the number of customers that enter the store on a given day is:
Xy = -150
x + y = 5
x + y = 5
x - x + y = -x + 5
y = -x + 5
xy = -150
x(-x + 5) = -150
x(-x) + x(5) = -150
-x² + 5x = -150
-x² + 5x + 150 = 0
-1(x²) - 1(-5x) - 1(-150) = 0
-1(x² - 5x - 150) = 0
-1 -1
x² - 5x - 150 = 0
x = -(-5) ± √((-5)² - 4(1)(-150))
2(1)
x = 5 ± √(25 + 600)
2
x = 5 ± √(625)
2
x = 5 ± 25
2
x = 2.5 ± 12.5
x = 2.5 + 12.5 or x = 2.5 - 12.5
x = 15 or x = -10
x + y = 5
15 + y = 5
- 15 - 15
y = -10
(x, y) = (15, -10)
or
x + y = 5
-10 + y = 5
+ 10 + 10
y = 15
(x, y) = (-10, 15)
The two numbers that add up to 5 and multiply to -150 are 15 and -10.
Answer:
0 to 900
Step-by-step explanation:
The three ordered pairs, (0, 250), (5, 575), and (10, 900) for the equation,
y = 65x + 250
imply that the y-axis should range from 0 to 900. The y-values from the ordered pairs are; 250, 575 and 900
Answer:
No. When all you want to do is estimate a population parameter, you should construct a confidence interval.
Step-by-step explanation:
In this case, there is no other prior estimation about the population to test (a hypothesis to nullify). The only thing you can do is construct a confidence interval of the proportion, where the standard deviation can be calculated in function of the proportion and the sample size.
The right answer is E: "No. When all you want to do is estimate a population parameter, you should construct a confidence interval."
$70 = 270 min
x = 1260 min
Where x is the charge of phone service per 1260 min.
Cross multiply:
1260 * 70 = 270 * x
88200 = 270x
88200/270 = x
x = 326.67
The total charge of cellular phone service for 1260 min is $326.67
