2. Write as an exponential expression : -X•-X•-X

X^3

x^3

Step-by-step explanation:

6 * 6 * 6 = 6^3

banana * banana * banana = banana^3

x * x * x = x^3

a) Standard Deviation = 2.74

b) Significantly Low = values below 24.52 (or equal)

Significantly High = values above 35.48 (or equal)

Step-by-step explanation:

This is binomial probability distribution problem.

Where n = 40 [groups of 40, total trials]

p = 0.75 [probability of success]

a)

The formula for standard deviation is:

We know  n = 40 and p = 0.75, so the standard deviation is:

b)

the range rule of thumb tells us that usual range of values is within 2 standard deviation of the mean. First let's calculate mean.

We know,

Mean = n * p = 40 * 0.75 = 30

So

Mean - 2* Standard Deviation = 30 - 2(2.74) = 24.52

and

Mean + 2* Standard Deviation = 30 + 2(2.74) = 35.48

Significantly Low = values below 24.52 (or equal)

Significantly High = values above 35.48 (or equal)