What is the value of the expression when a = 3 and b = 2?3a^3 + 2b^3
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A. 78
B. 97
C. 135
D. 745

Please don't respond with the answer alone, I'd like to know how to work through it. :)

The point estimates for the mean and standard deviation of the given data is respectively; 68 and 17.6

What is point Estimate?

A) To find the point estimate of the mean, we add all up all the data and divide by the number of values.

Thus;

∑x = 57 + 61 + 86 + 87 + 72 + 73 + 19 + 56 + 81 + 79 + 83 + 75 = 816

n = 12 numbers

Thus;

mean = ∑x/n = 816/12

Mean = 68

B) To find the estimate of the standard deviation, we would get it from the formula;

s = √[(n*(∑x²) - (∑x)²)/n(n - 1)]

∑x² = 572 + 612 + 862 + ... + 742 = 59,010

s = √[ (12*(59,010) - (816)²)/(12)(11)]

s = 17.6

Read more about Point Estimate at; brainly.com/question/9562180

Answer:

-3/2

Step-by-step explanation:

(5a + 3) / (a^2 - 1) when a = -3, substitute all values of "a" for -3:

(5(-3) + 3) / ((-3)^2 - 1)

(-15 + 3) / (9 - 1)

(-12) / (8)

Simplify:

- 3/2

Answer:

22.73 km.

Step-by-step explanation:

To find the average distance covered by the car in 1 hour, we can use the concept of speed or velocity.

Speed is defined as the distance traveled divided by the time taken. In this case, the car covers a distance of 50 km in 2.2 hours.

To find the average speed of the car, we divide the total distance by the total time:

Average speed = Total distance / Total time

Average speed = 50 km / 2.2 hours

Simplifying this calculation, we find that the average speed of the car is approximately 22.73 km/h.

Since speed is defined as the distance covered per unit of time, we can conclude that the car covers an average distance of 22.73 km in 1 hour.

Therefore, the average distance covered by the car in 1 hour is approximately 22.73 km.