Another random sample of the number of friends for 30 users of the
website
is shown at the left. Use this sample to find another point
estimate for
a. Find the sample mean.
b. Estimate the mean number of friends of the
population.
(Updated to see Data Set, My Apologies.)
- Try It Yourself 1 Another Random Sample Of The Number Of Friends For 30 Users Of The Website Is Shown At The Left Use 1 (84.86 KiB) Viewed 22 times
Try It Yourself 1:
Another random sample of the number of friends for 30 users of the
website
is shown at the left. Use this sample to find another point
estimate for
a. Find the sample mean.
b. Estimate the mean number of friends of the
population.
(Updated to see Data Set, My Apologies.)
sample mean is decreased by increasing n, it becomes less variable. 58 74 EXAMPLE 1 Finding a Point Estimate A social networking website allows its users to add friends, send messages, and update their personal profiles. The following represents a random sample of the number of friends for 40 users of the website. Find a point estimate of the population mean p. (Adapted from Facebook) 140 105 130 97 80 165 232 110 214 201 122 98 65 88 154 133 121 82130 211 153 114 77 51 247 236 109 126 132 125 149 122 59 218 192 90 117 105 Solution The sample mean of the data is x 5232 = 130.8. So, the point estimate for the mean number of friends for all users of the website is 130.8 friends Try It Yourself 1 Another random sample of the number of friends for 30 users of the website is shown at the left. Use this sample to find another point estimate for p. a. Find the sample mean b. Estimate the mean number of friends of the population. Answer: Page A39 40 Sample Data Number of Friends 162 114 131 87 108 63 249 135 172 196 127 100 146 214 80 55 71 130 95 156 201 227 137 125 145 179 74 215 137 124
n 40 Sample Data Number of Friends 162 114 131 87 108 63 249 135 172 196 127 100 146 214 80 55 71 130 95 156 201 227 137 125 145 179 74 215 137 124 So, the point estimate for the mean number of friends for all users of the website is 130.8 friends. ► Try It Yourself 1 Another random sample of the number of friends for 30 users of the website is shown at the left. Use this sample to find another point estimate for u. a. Find the sample mean. b. Estimate the mean number of friends of the population. Answer: Page A39