Shoe sizes for men in the united states have a distribution that is bell shaped where = 10 and = 1.5. using the empirical rule, what percent of men have a shoe size between 7 and 13?

Step-by-step explanation:

Pictured is a normal distribution curve.  The mean is in the middle and each line going from the middle is either adding or subtracting the standard deviation.  Our mean is 10, so 10 goes in the middle, and the line to the right of 10 is 10+1.5=11.5.  The next line to the right of that is 11.5+1.5=13.  The line to the right of that is 13+1.5=14.5.

To the left of the mean we have 10-1.5=8.5.  To the left of that we have 8.5-1.5=7.  To the left of that we have 7-1.5=5.5.  You can see in the image what the percentage is within each separation.  From a size 7 to a size 13 we have the percentages 13.5+34+34+13.5=95%

In the greater realm of things, this statistic tells a shoe store manager that since 95% of men polled wear a shoe size between 7 and 13, it would be cost efficient for him to keep an abundance of these sizes on hand.  The greatest majority of men polled (68%) wear from a size 8.5 to a size 11.5.  

the ratio of white tiles to blue tiles is 48: 16. the ratio in it's simplest form is 3: 1.

step-by-step explanation:

ratio: take the first number and add a colon next to it, then add the second number after that. make sure the ratio order matches up with the written problem!

simplest form: we can simplify the ratio 48 : 16 by dividing both terms by the greatest common factor (gcf).

the gcf of 48 and 16 is 16.

divide both terms by 16:

48 ÷ 16 = 3

16 ÷ 16 = 1

reducing to simplest form:

48 : 16 = 3 : 1

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.