Question

The Downtown Parking Authority of Tampa, Florida, reported the following information for a sample of 231 customers on the number of hours cars are parked and the amount they are charged.

Number of Hours	Frequency			Amount Charged
1		19		$	3
2		35			8
3		48			13
4		42			16
5		35			20
6		16			24
7		5			27
8		31			30
		231

Find the mean and the standard deviation of the number of hours parked. (Do not round intermediate calculations. Round your final answers to 3 decimal places.)

Mean
Standard deviation

1	How long is a typical customer parked? (Do not round intermediate calculations. Round your final answers to 3 decimal places.)

The typical customer is parked for

hours

2	Find the mean and the standard deviation of the amount charged. (Do not round intermediate calculations. Round your final answers to 3 decimal places.)

3.Mean
4.Standard deviation

Answer 1

dividing each value with total value of 231:

Hours	probability
4	0.082
6	0.152
9	0.208
13	0.182
14	0.152
16	0.069
18	0.022
22	0.134

x	P(x)	xP(x)	x2*P(x)
1	0.082	0.082	0.082
2	0.152	0.304	0.608
3	0.208	0.624	1.872
4	0.182	0.728	2.912
5	0.152	0.760	3.800
6	0.069	0.414	2.484
7	0.022	0.154	1.078
8	0.134	1.072	8.576
		4.138	21.412
E(x) =μ=	ΣxP(x) =		4.138
E(x2) =	Σx2P(x) =		21.412
Var(x)=σ2 =	E(x2)-(E(x))2=		4.289
std deviation=	σ= √σ2 =		2.071

Mean =4.138 (please try 4.134 if this comes wrong and reply)

  Standard deviation =2.071 (please try 2.075 if this comes wrong and reply)

1)

How long is a typical customer parked =4.138 (please try 4.134 if this comes wrong and reply)

2)

Mean =16.388 (please try 16.372 if this comes wrong and reply)

  Standard deviation =7.799 (please try 7.817 if this comes wrong and reply)