Answer:
A sample size of 79 is needed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of
.
For this problem, we have that:

The margin of error is:
95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
What sample size is needed if the research firm's goal is to estimate the current proportion of homes with a stay-at-home parent in which the father is the stay-at-home parent with a margin of error of 0.09?
A sample size of n is needed.
n is found when M = 0.09. So






Rounding up to the nearest whole number.
A sample size of 79 is needed.
I have no clue I just need the points have a good day tho :)
Answer:
<h2>The x-coordinate after the rotation is -10.</h2>
Step-by-step explanation:
A 810° rotation is equal to a 90° rotation. So, the transformation described gives the same result than rotating 90° only.
A 90° counterclockwise rotation is defined by the rule

The given coordinate is
. Using the rule, we have

Therefore, the x-coordinate after the rotation is -10.
Answer:
The total mechanical energy is 0.712 J.
Step-by-step explanation:
A blue 573 g mobile is moving on a metal rail. If on the mobile, the spring exerts a force to the right of modulus 0.85 N and in the indicated position the kinetic energy of the mobile-spring system is 0.47 J and its elastic potential energy is 0.242 J. Determine the mechanical energy of the system mobile-spring in the position shown as indicated in the figure.
The total mechanical energy is given by the sum of the kinetic energy and the potential energy.
Kinetic energy = 0.47 J
Potential energy = 0.242 J
The total mechanical energy is
T = 0.47 + 0.242 = 0.712 J