A social scientist measures the number of minutes (per day) that a small hypothetical population of college students spends online. Student Score Student Score A 58 F 92 B 77 G 99 C 87 H 84 D 87 I 99 E 91 J 22 (a) What is the range of data in this population? min (b) What is the IQR of data in this population? min (c) What is the SIQR of data in this population? min (d) What is the population variance?

Respuesta :

Answer:

The range of the data = 99 -22 = 77min

The mean of the dataset is given as

The IQR  = 92 - 77 = 15 min

SIQR = IQR / 2 = 15 / 2 = 7.5 min

variance = 55.05 min

Step-by-step explanation:

First we need to arrange the data in ascending or descending order

22 ,58, 77, 84, 87, 87,91, 92, 99, 99 in ascending order

The range of the data is calculated by substracting the numbers at the extreme that is the lowest number subtracted from the highest number

range = 99 - 22 =  77min

The IQR stands for Inter-quartile range Q3 - Q1 where

Q1  is the middle value in the first half of the data set. i.e

Q1 is the middle of 22 ,58, 77, 84, 87 which is  77

Q1 = 77 min

Q3  is the middle value in the second half of the data set. i.e

Q3 is the middle of 87,91, 92, 99, 99 which is  92

Q1 = 92 min

Therefore IQR = Q3 - Q1 = 92min - 77min = 15 min

The SIQR stands for the semi-interquartile range. it is calculated by IQR / 2

SIQR = 15 / 2 = 7.5 min

To calculate the population variance we need to get the mean say X

The mean is the data point at the center. Since the dataset is even, there are two of them. which is 87 and 87

Therefore the mean is X = (87 + 87)/ 2 = 87

The variance = ∑[tex](X-x)^{2} /n[/tex]

where X is the mean = 87

x is a datapoint on the given dataset

n is the datasize = 10

variance =  [tex]((22-87)^{2} + (58-87)^{2} + (77-87)^{2} + (84-87)^{2} + (87-87)^{2} + (87-87)^{2} + (91-87)^{2} + (92-87)^{2} + (99-87)^{2} + (99-87)^{2} ) /10[/tex]

variance = [tex]((-65)^{2} + (-29)^{2} + (-10)^{2} + (-3)^{2} + (0)^{2} + (0)^{2} + (4)^{2} + (5)^{2} + (12)^{2} + (12)^{2} ) /10[/tex]

variance = [tex]((4225) + (841) + (100) + (9) + (0) + (0) + (16) + (25) + (144) + (144) ) /10[/tex]

variance = 5505/10

variance = 550.5 min

Answer:

Range =77

IQR=15

SIQR=7.5

Variance=550.5

Step-by-step explanation:

Range:

First find the lowest and the highest number in the data and then subtract high with the low to find the range. 99-22=77.

IQR:

Ascend the data from low to high like this:

22 58 77 84 87 87 91 92 99 99

Then break into two half

22 58 77 84 87 | 87 91 92 99 99

Find the median of all the two half

77 is rhe median in the first half and 92 is the median in the second half.

Then subtract them: 92-77=15 IQR

SIQR:

Divide the IQR/2

Hence 15/2=7.5.

Variance:

Find the mean of the data first i.e. 79.6

variance = 5505/10

variance = 550.5