If your school have 255 students, about how many would you expect to have an iq less than 70?

6

Step-by-step explanation:

Assuming a mean of 100 and standard deviation of 15, 70 is 2 standard deviations below the mean.

According to the empirical rule, 95% of the population is within ±2 standard deviations.  Which means half of that, or 47.5%, is between 0 and -2 standard deviations.  Since 50% of the population is below 0, then 2.5% is below -2 standard deviations.

2.5% of 255 is approximately 6.

send it over

step-by-step explanation:

rick has $1400 and sally has $1500

step-by-step explanation:

to find amount of money rick has after 10 years :

principal = $1000 , time = 10 years , rate = 4% annually

to find amount of money sally has after 10 years :

her friend gives to pay her $50 per year, therefore money she has after 10 years = 50 × 10 = $500

also, sally gets $1000 after 10 years,

therefore, total amount of money sally has after 10 years = 500 + 1000 = $1500

so, after 10 years : rick has $1400 and sally has $1500