The Z-table (attached at the end of this lab) give the area to the of 1.38. Look up 1.38 in the left table, and we find that the area to the left of 1.38 is 0.9162. This leaves a percentage of 0.0838 to the right. Answer: 8.38% of days have a temperature above 76 degrees. Q5] Now your turn. Approximately what percentage of the time are the temperatures in the it’s pool: Greater than 78 degrees? Below 70 degrees? Between 60 and 70 degrees? Part 4 Using R Commander – The Rcmdr software package will compute normal probabilities as the well. Let’s reconsider example above, where the mean is 72.4, the standard deviation is 2.6, and interested in we’re the percentage of days above 76 degrees. Go to Distributions Continuous distributions Normal distribution Normal probabilities. Plug in the value soon, along with the mean and standard deviation. If you y want the percentage 75 degrees, select the If you want the below “lower tale” radio button. percentage use the above 75 degrees, “upper tale” radio button. We find that the percentage is 0.0831, similar to what we found by hand in Part 3 of this lab. Q6] Redo the parts of Q5 using R commander. Part 5 Normal Percentiles – The previous work of this lab gave us an observation value and asked for a percentage related to it. Example: What percentage of days would we expect to have a temperature of over 76 degrees?
The Z-table (attached at the end of this lab) give the area to the left of 1.38. Look up 1.38 in the table, and we find that the area to the left of 1.38 is 0.9162. This leaves a percentage of 0.0838 to the right. Answer: 8.38% of days have a temperature above 76 degrees. Q5] Now it’s your turn. Approximately what percentage of the time are the temperatures in the pool: Greater than 78 degrees? Below 70 degrees? Between 60 and 70 degrees? Part 4 – Using R Commander The Rcmdr software package will compute normal probabilities as well. Let’s reconsider the example above, where the mean is 72.4, the standard deviation is 2.6, and we’re interested in the percentage of days above 76 degrees. Go to Distributions Continuous distributions Normal distribution Normal probabilities. Plug in the y value soon, along with the mean and standard deviation. If you want the percentage below 75 degrees, select the “lower tale” radio button. If you want the percentage above 75 degrees, use the “upper tale” radio button. We find that the percentage is 0.0831, similar to what we found by hand in Part 3 of this lab. Q6] Redo the parts of Q5 using R commander. Part 5 – Normal Percentiles The previous work of this lab gave us an observation value and asked for a percentage related to it. Example: What percentage of days would we expect to have a temperature of over 76 degrees?