Download 3. Find the mean, median, and mode of the data, if possible

3. Find the mean, median, and mode of the data, if possible. Fourteen different second- year medical
students measured the blood pressure of the same person. The systolic reading in (mmhg) are listed
below: 140 118 138 130 140 151 127 130 146 130 130 118 143 136
The mean blood pressure is ______ mmhg.
Ans:
Mean = (140+118+138+130+140+151+127+130+146+130+130+118+143+136)/14 = 134.0714
4.You are applying for a job at two companies. Company A offers starting salaries u = $34,000 and 0 =
$3,000. Company B offers starting salaries u=$34,000 and 0= $7,000. From which company are you more
likely to get an offer of $40,000 or more?
Ans. Company B, since its standard deviation is higher both means being same. Thus in terms of normal
score, 40000 is nearer to the mean value for company B.
6. An auction company sold 15 hand-held computers last month. The final prices (in dollars) at which the
items are sold are as follow: 229, 247, 248, 236, 247, 252, 245, 229, 217, 229, 248, 229, 205, 213, 231;
Stems: 20, 21, 22, 23, 24, 25
a. construct a stem and leaf plot
Ans
20: 5
21: 3 7
22: 9 9 9 9
23: 1 6
24: 5 7 7 8 8
25: 2
b. summarize what this plot tells you about the data
Ans
This plot tells that most number of computers was sold at prices in range of $220-229 and $240-249. For
other prices, sales were lower.
7. An insurance company crashed four cars of the same model at 5 miles per hour. The cost of repairs
for each of the four crashes were $426, $438, $487, and $216. Compute the mean, median, and mode
cost of repair. Compute the mean cost of repair. Select the correct choice below, and if necessary, fill in
the answer box to complete your choice.
a. the mean cost of repair is $________. (round to the nearest cent)
Ans
Mean = (426+438+487+216)/4 = 391.75
Median = (426+438)/2 = 432
Mode doesn’t exist.
9. find the range, mean, variance, and standard deviation of the population data set. 23, 14, 4, 10, 9
Ans
Range = 23 – 4 = 19
Mean = (23+14+4+10+9)/5 = 12
Variance = ((23-12)^2 + (14-12)^2+(4-12)^2+(10-12)^2+(9-12)^2)/(5-1) = 50.5
Standard deviation = sqrt(50.5) = 7.106335
10. Heights of men on a baseball team have a bell-shaped distribution with a mean of 178 cm and a
standard deviation of 9 cm. Using the empirical rule, what is the approximate percentage of the men
between the following values.
Ans
a. 169 cm and 187 cm
percentage within 1 standard deviation of mean = 68%
b. 151 cm and 205 cm
percentage within 3 standard deviation of mean = 99.7%