Which of shakina's statements regarding acceleration and velocity is false? "when the acceleration is negative, the velocity can be either negative or positive." "when the acceleration is negative, the velocity must also be negative."?

Let's start by imagining a rock being thrown to the air.
Let's say that going up is the positive direction and so, going down is the negative.
The acceleration is pointing down (because of gravity) so it's always negative. While the rock is going up, it's velocity/speed is positive, but the acceleration is negative.
While the rock is going down, both acceleration and speed are negative.
This shows that the first statemente is true, but the second is false.
You can also think that if you define going DOWN as the POSITIVE direction, you can have both positive acceleration and speed, or positive acceleration and negative speed.

So the answer for this case would be n=132 rounded up to the nearest integer

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

represent the sample mean for the sample  

population mean (variable of interest)

represent the population standard deviation

n represent the sample size  

Solution to the problem

The margin of error is given by this formula:

   (a)

And on this case we have that ME =2 and we are interested in order to find the value of n, if we solve n from equation (b) we got:

  (b)

The critical value for 90% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.05;0;1)", and we got , replacing into formula (b) we got:

So the answer for this case would be n=132 rounded up to the nearest integer