Exam 3: Describing, Exploring, and Comparing Data

Approximately what percentage of apple diameters is greater than the 66th percentile?

Listed below are the arrival delay times (in minutes)of randomly selected flights between New York's JFK airport to Los Angeles (LAX). Negative values correspond to flights that arrive before their schedule time and positive values represent delays. Calculate the range of the data and the standard deviation. Can the standard deviation be negative? -15 -18 -32 -21 -9 -32 11 2

The race speeds (in minutes)for the top eight cars in a 200-mile race are listed below. Use the range rule of thumb to estimate the standard deviation. Round results to the nearest tenth. 181.0 180.6 189.2 182.2 175.6 180.0 177.9 181.8

The mean height of a basketball team is 6 feet with a standard deviation of 0.2 feet. The team's center is 6.9 feet tall. Find the center's z score. Is his score unusual?

The test scores of 40 students are listed below. Find P85 30 35 43 44 47 48 54 55 56 57 59 62 63 65 66 68 69 69 71 72 72 73 74 76 77 77 78 79 80 81 81 82 83 85 89 92 93 94 97 98

A department store has daily mean sales of $ 28,372.72. The standard deviation of sales is $2000. On Tuesday, the store sold $34,885.21 worth of goods. Find Tuesday's z score. Was Tuesday a significantly good day?

The owner of a manufacturing plant employs eighty people. As part of their personnel file, she asked each one to record to the nearest one-tenth of a mile the distance they travel one way From home to work. The distances for a random sample of six employees are listed below: 26 32 29 16 45 19 Find the variance for the given data.

A store manager kept track of the number of newspapers sold each week over a seven-week period. The results are shown below. 81 71 202 113 269 248 242 Find the median number of newspapers sold.

Explain how two data sets could have equal means and modes but still differ greatly. Give an example with two data sets to illustrate.

When finding percentiles, if the locator L is not a whole number, one procedure is to interpolate so that a locator of 23.75, for example, leads to a value that is 3/4 of the way Between the 23rd and 24th scores. Use this method of interpolation to find P75 for the set of Test scores below. 51 54 64 68 72 74 76 83 94 94 99

The mean of a set of data is 108.06 and its standard deviation is 115.45. Find the z score for a value of 489.67.

A student earned grades of 84, 78, 84, and 72 on her four regular tests. She earned a grade of 78 on the final exam and 86 on her class projects. Her combined homework grade was 87. The Four regular tests count for 40% of the course grade, the final exam counts for 30%, the project Counts for 10%, and homework counts for 20%. What is her weighted mean grade? Round to One decimal place.

Use the following duration times (seconds)of 24 eruptions of the Old Faithful geyser in Yellowstone National Park. The duration times are sorted from lowest to highest. 110 120 178 213 234 234 235 237 240 243 245 245 250 250 251 252 254 255 255 259 260 266 269 273 Describe how to calculate the limits to determine outliers for this data set? Identify any outliers.

In a data set with a range of 55.4 to 105.4 and 400 observations, there are 276 observations with values less than 86. Find the percentile for 86.

Construct a data set for which the range is misleading as a measure of variation. the range is misleading and suggest an alternative measure of variation.

Dave is a college student contemplating a possible career option. One factor that will influence his decision is the amount of money he is likely to make. He decides to look up the average salary of graduates in that profession. Which information would be more useful to him, the mean salary or the median salary. Why?

An engineer is designing a machine to manufacture gloves and she obtains the following sample of hand lengths (mm)of randomly selected adult males based on data gathered: 173 179 207 158 196 195 214 199 Define this data set as discrete or continuous. The hand lengths is what type of level of measurement? Compare the mean and median for this data set and if you can draw any conclusions from these values.

Jorge has his own business as a painter. The amounts he made in the last five months are shown below: \ 2426 \ 2463 \ 1451 \ 2154 \ 1119 Find the mean, median, and range of the data.

A test score of 48.4 on a test having a mean of 66 and a standard deviation of 11. Find the z score corresponding to the given value and use the z score to determine whether the value is Significant. Consider a score to be significant if its z score is less than -2.00 or greater than 2.00. Round the z score to the nearest tenth if necessary.

The textbook defines significantly low or high values as those data points with z scores less than z =−2.00 or z scores greater than z = 2.00. Comment on this definition with respect to Chebyshev's theorem; refer specifically to the percent of scores which would be defined as significant according to Chebyshev's theorem.