A sample of wires coming off the production line was tested for tensile strength. The statistical results (in PSI) were the following: Arithmetic mean 500 Median 500 Mode 500 Standard deviation 40 Quartile deviation 25 Mean deviation 32 Range 240 Sample size 100 According to the Empirical rule, the middle 95% of the wires tested had a tensile strength between approximately what two values

The middle 95% of the wires tested had a tensile strength between approximately 420 PSI and 580 PSI

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean = 500

Standard deviation = 40

According to the Empirical rule, the middle 95% of the wires tested had a tensile strength between approximately what two values

By the empirical rule, within 2 standard deviations of the mean

500 - 2*40 = 420 PSI

500 + 2*40 = 580 PSI

The middle 95% of the wires tested had a tensile strength between approximately 420 PSI and 580 PSI

step-by-step explanation:

a.   since the profit made in 2012 is equal to the profit made in 2014, the profit is           symmetric about the line y = 120,000.

step-by-step explanation:

given that megan owns a clothing boutique.

the profits of 2010, 11, are recorded and shown as follows:

years since     2010 0     1     2     3       4       5

profits made in 1000's   39       84     111     120   111     84

we find that profit gradually increases form 2010 to 2013 upto 120,   then starts decreasing.

the profits for 2012 and 2014 are the same while that of 2011 and 2015 are also the same.

this shows that there is symmetry about the line profit = 120000

hence answer is:

a.   since the profit made in 2012 is equal to the profit made in 2014, the profit is           symmetric about the line y = 120,000.

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solution:

as, mean is defined as sum of all the observations divided by total number of observations.

and , median is mid value of the data whether arranged in ascending order or descending order.

consider, roadsters:

2,3,4,5,6,7,8,9

mean =

also, median= , because number of observations is even, so median is mean of two mid values.

now, coming to bandits

2,3,4,5,6

mean =  

median = 4, as number of observations is odd.

so, roadsters has greater median as well mean than bandits.

→option a is true about the repairs performed on 2 types of cars:

bandits have lower median and mean than roadsters.