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The mean number of minutes that android phone users spend on an app is 8.2 minutes. Suppose the standard deviation is 1 minute. Take a sample of 60 What are the mean, standard deviation for the sample mean number of app engagement by a tablet user? and Find the probability that the sample mean is between 8 and 8.5 minutes. 2.) In a recent study, the mean age of online job search website users is 34 years. Suppose the standard deviation is 15 years. Take a sample of size n=100. a.) What are the mean, and standard deviation for the sample mean ages of tablet users? Find the probability that the sample mean age is more than 30 years
If cos(๐ ) = 3/5 and tan( ๐ ) < 0 , find the exact value of each of the remaining trigonometric functions of ๐
A lawyer claims that the average years of settling criminal cases filed before courts is three
and a half years. To test the claim, a watchdog organization randomly selected 35 criminal
cases and recorded the years the cases took before the courts have been rendered verdicts.
The sample mean was 4 years with a standard deviation of three and a half years. Do the
data gathered by the said organization provide sufficient basis to accept the claim of the
lawyer? Use 0.05 level of significance.
A company claimed that their N95 face mask has a mean filtration efficiency rate of
95%. A group of student researcher wanted to verify this claim. They bought and tested
40 of their N95 face masks. They found out that the average filtration efficiency rate of
these face mask was 90% with a standard deviation of 4%. Test the claim at 5% level
of significance and assume that the population is approximately normally distributed.
Aย 198.4 and a 318.3-kg cart approach each other on a horizontal air track. They collide and stick together. After the collision their total kinetic energy isย 1011. What is the speed after the collision?
If the work required to speed a car from 10 km/h to 20 km/h is 5.0 x 10^3 J, what would be the work required to increase its speed from 20 km/h to 30 km/h.
A survey unofficially claimed that in every five young executives, only one practices good reading habits.
a. What is the probability that out of 10 young executives, two executives practice good reading habits?
b. What is the probability that at least five out of 20 young executives practice good reading habits?
A circular loop of wire of radius 0.25 cm is expected to an external magnetic field that is perpendicular to the plane of the loop. For a time, the magnetic field decreases at a rate of 0.0035 T/s. What is the magnitude of the induced electromagnetic force in the loop?
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A flexible rectangular coil of wire with 150 loops is stretched in such a way that its dimension changes from 5 cm x 8 cm to 7 cm x 11 cm in 0.15 s in a magnetic field of 25T that is 30 degrees relative to the plane of the coil.
a. Calculate the induced EMF
b. How much energy in joules was dissipated in the circuit if the total resistance is 100ฮฉ?
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A truck starts from rest and moves with a
constant acceleration of 5.0 m/s2
. Find its
speed and the distance travelled after 4.0
seconds has elapsed.
