Megan put $2400 in a savings account earning 2% interest compounded semi-annually 7 years ago. How much money is in her account now?

Money in Megan saving accounts is $2758.74

Step-by-step explanation:

Formula for compound interest is given as,

where, m : number of compounding periods per year

i : rate per compounding period = r/ m

n : total no. of compounding periods = m * no. of years.

P : principal ( present value)

A : amount ( future value ) at the end of n periods

Now calculate the value of above terms.

Since it is given that interest is compounded semi annually.

Therefore value of m is m = 2.

Given that rate is 2% that is, r = 0.02

Also number of years is 7 that is, t = 7

Therefore formula becomes,

Substituting the values in the formula,

Simplifying,

Rounding to two decimal places, A = $ 2758.74

Therefore, Megan has total of $ 2758.74 in her saving account.

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.