Respuesta :
Answer:
the mean is 82.75
Step-by-step explanation:
Amount Frequency Mid Point fx
0-19.99 16 9.995 159.92
20.00-39.99 13 29.995 389.935
40.00-59.99 21 49.995 1049.895
60.00-79.99 19 69.995 1329.905
80.00-99.99 12 89.995 1079.94
100.00-119.99 10 109.995 1099.95
120.00-139.99 7 129.995 909.965
140.00-159.99 8 149.995 1199.96
160.00-179.99 7 169.995 1189.965
180,00-199.99 1 189.995 189.995
200.00-219.99 3 209.995 629. 985
220.00-239.99 2 229.995 459.99
240.00-259.99 1 249.995 240.995
∑ 120 9930.4
Mean = ∑fx/∑x
Mean = 9930.4/120=82.7533 = 82.75
Answer: The mean amount spent on Valentine's day is;
$82.83
Step-by-step explanation: To find the mean amount we first arrange the numbers in a frequency table, then solve.
STEP1:
AMOUNT FREQUENCY
0-19.99 16
20.00-39.99 13
40.00-59.99 21
60.00-79.99 19
80.00-99.99 12
100.00-119.99 10
120.00-139.99 7
140.00-159.99 8
160.00-179.99 7
180,00-199.99 1
200.00-219.99 3
220.00-239.99 2
240.00-259.99 1
STEP 2: Find the center of each amount, to do this we have to find the average value of the amounts.
For the first amount is;
(0+19.99)/2 = 9.995
For the second amount is;
(20+39.99)/2 =29.995
Solving this for all the amount. Therefore the table comes
AMOUNT FREQUENCY
9.995 16
29.995 13
49.995 21
69.995 19
89.995 12
109.995 10
129.995 7
149.995 8
169.995 7
189.995 1
209.995 3
229.995 2
249.995 1
STEP 3: multiple each amount in step 2 with the frequency.
For the first amount;
9.995×16 = 159.92
For the second amount;
29.995×13= 389.935
For the third amount;
49.995×21= 1049.895
For the fourth amount;
69.99×19= 1329.81
For the fifth amount;
89.995×12=1079.94
For the six amount;
109.995×10= 1099.95
For the sixth amount;
129.995×7= 909.965
For the seventh amount;
149.995×8= 1199.96
For the eight amount;
169.995×7= 1189.965
For the ninth amount;
189.995×1= 189.995
For the tenth amount;
209.995×3= 629.985
For the eleventh amount;
229.995×2=459.99
For the twelveth amount;
249.995×1= 249.995
STEP 4: Sum up all the answers from the multiplication in step 3
Therefore;
159.92+389.935+1049.895+1329.81+1079.94+1099.95+909.965+1199.96+1189.965+189.995+629.985+459.99+629.985+459.99+249.995 = 9939.995
STEP 5: divide the sum of the value seen in step 4 with the total number of frequency to get the mean value.
The total number of frequency is 120
Therefore;
9939.305÷120=82.827541
Take the value to two decimal place, it becomes;
$82.83 this is the mean value of money spent on Valentine's day.
