According to data from 2015, women's shoe sales in the US are roughly normally distributed by shoe size with a mean of size 8 and a standard deviation of 1.25 sizes. a) If a women's shoe sold in the US is a size 7.5, what is the z-score?

b) What size of women's shoe would have a z-score of 1.3?

c) If a women's shoe sold in the US is a size 9, what is the z-score and percentile? z-score:
Percentile:

d) What size of women's shoe would have a z-score of -1.5? What percentile is that? shoe size:
Percentile:

e) What women's shoe size represents the 80th percentile? z-score:
shoe size:

Which recursive formula can be used to determine the total amount of money earned in any year based on the amount earned in the previous year? f(n+1)=f(n)+5

In tossing one coin 10 times, what are your chances for tossing a head? a tail? 2. in tossing one coin 100 times, what are your chances for tossing a head? a tail? 3. in tossing one coin 200 times, what are your chances for tossing a head? a tail? deviation = ((absolute value of the difference between expected heads and observed heads) + (absolute value of the difference between expected tails and observed tails)) divided by total number of tosses. this value should always be positive. 4. what is the deviation for 10 tosses? 5. what is the deviation for the 100 tosses? 6. what is the deviation for 200 tosses? 7. how does increasing the total number of coin tosses from 10 to 100 affect the deviation? 8. how does increasing the total number of tosses from 100 to 200 affect the deviation? 9. what two important probability principles were established in this exercise? 10. the percent of occurrence is the obtained results divided by the total tosses and multiplied by 100%. toss the coins 100 times and record your results. calculate the percent occurrence for each combination. percent head-head occurrence: percent tail-tail occurrence: percent head-tail occurrence:

What is the expression in factored form? 225x^2 - 144 a. 9(5x+4)^2 b. 9(5x-4)^2 c. 9(4x+5)(4x-5) d. 9(5x+4)(5x-4)