Lin Ying belongs to an athletic club. In 800 m races her times are normally distributed with mean 128 seconds and standard deviation 4 seconds.
(a) What is the probability of her time in an 800 being between 120 and 130 seconds?
(b) What time will she beat in 70% of her races?
Julie belongs to the same club. In 800 m races 85% of her times are less than 140 seconds and 70% are less than 135 seconds. Her times are normally distributed.
(c) Find the mean and standard deviation of Julie's times, each correct to two significant figures.
(d) What is the probability that in an 800 m race Lin Ying will beat Julie?
(e) The club has to choose one of these two athletes to enter a major competition. In order to qualify for the final rounds it is necessary to achieve a time of 114 seconds or less in the heats. Which athlete should be chosen and why?

Nine of the times for the first race were at least 16 seconds

Step-by-step explanation:

Here we have from the scatter plot, the times are given as

Time               Frequency

19                          2

18                          2

17                          2

16                          3

15                          1

Therefore, total number of times that are above 16 seconds in the first race is

3 + 2 + 2 + 2 = 9

Therefore, the first option is correct

Step-by-step explanation:

The answer is below. Plesetake a look and it will help you

see below

step-by-step explanation:

7.   there are 10 data points in the set.   the middle point is between 5 and 6.   the middle point in the top half is 8   and the middle point in the bottom half is 3. to find the iqr , take point 8 and subtract point 3

mid term   point 8 = 100   point 3 = 88

iqr = 100-88 = 12

final   point 8 = 93   point 3 = 78

iqr = 93 - 78 = 15

the final has the greatest iqr

6.   b - there is a high data value that causes the data set to be asymmetrical for the males: the data for males are high and asymmetrical .   there is an outlier for the males that skews the data

5.   the   iqr is a better measure of spread for the movies and basketball games.   since the basketball game has an outlier, we do not want to use standard deviation for measurement.  

3.   the exam median is much higher than the class median.   the median line is farther to the right on the exams

2.   there is no way to tell what the means are from the box and whisker plots.  

answer: domain and range mean all possible values of x and y that could be substituted to the inequality. a solution means all possible values that make the inequality statement true. so while the range is still all real numbers, the solution is the shaded area, for which y will always be greater than the line of the function.