Question

1. Find the​ (a) mean,​ (b) median,​ (c) mode, and​ (d) midrange for the given sample data.

An experiment was conducted to determine whether a deficiency of carbon dioxide in the soil affects the phenotype of peas. Listed below are the phenotype codes where 1=smooth-yellow​,2=smooth-green​, 3=wrinkled-yellow​, and 4=wrinkled-green.

Do the results make​ sense?

3

1

3

4

4

1

2

4

1

4

3

3

3

3

​(a) The mean phenotype code is _____.

2. Statistics are sometimes used to compare or identify authors of different works. The lengths of the first 10 words in a book by Terry are listed with the first 10 words in a book by David. Find the mean and median for each of the two​ samples, then compare the two sets of results.

​Terry:	2	2	2	11	8	9	2	6	3	3
​David:	3	4	3	2	3	1	3	1	4	3

The mean number of letters per word in​ Terry's book is _____.

3. Refer to the data set of​ times, in​ minutes, required for an airplane to taxi out for​ takeoff, listed below. Find the mean and median. How is it helpful to find the​ mean?

36	35	25	11	26	29	30	32	19	39	45	31
31	14	40	27	24	48	10	43	18	30	45	31
13	34	17	16	23	40	47	31	27	34	17	47
28	35	26	44	14	43	30	14	30	18	38	13

Click the icon for the taxi out takeoff data.

Find the mean and median of the data set using a calculator or similar data analysis technology.

The mean of the data set is _____ minutes.

4. Find the mean of the data summarized in the given frequency distribution. Compare the computed mean to the actual mean of 50.4 miles per hour.

Speed​ (miles per​ hour)	42−45	46−49	50−53	54−57	58−61
Frequency	29	12	6	3	2

The mean of the frequency distribution is _____ miles per hour.

5.Six different​ second-year medical students at Bellevue Hospital measured the blood pressure of the same person. The systolic readings​ (in mmHg) are listed below. Find the​ range, variance, and standard deviation for the given sample data. If the​ subject's blood pressure remains constant and the medical students correctly apply the same measurement​ technique, what should be the value of the standard​ deviation?

126   126   138   125   137   134

Range= ______ mmHg

Answer 1

1.a. Mean is

b. The median is the middle number in a sorted list of numbers. So, to find the median, we need to place the numbers in value order and find the middle number.

Ordering the data from least to greatest, we get:

1   1   1   2   3   3   3   3   3   3   4   4   4   4   

As you can see, we do not have just one middle number but we have a pair of middle numbers, so the median is the average of these two numbers:

Median=

c. The mode of a set of data is the value in the set that occurs most often.

Ordering the data from least to greatest, we get:

1   1   1   2   3   3   3   3   3   3   4   4   4   4   

We see that the mode is 3 .

d. Midrange is  (max + min) / 2=(4+1)/2=2.5