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2. A fire-detection device uses three-temperature-sensitive cells acting independently of
one another in such a manner that any one or more can activate the alarm. Each cell has
a probability p = 0.8 of activating the alarm when the temperature reaches 100° or
higher. Let X represent the number of cells activating the alarm when the temperature
reaches 100°. Find:
a) the probability distribution of X;
b) the expected value; and
c) the variance for the random variable X.
A random sample of size 36 was taken from a population distributed as Nμ,3.92.The value of the sample x was 15.6. i. Find a 90% confidence interval for μ. (5mks)
It is believed that value of μ is 17. Use your confidence interval to comment on this belief.(2mks)
1. Two small conducting and identical spheres A and B have charges -32nC and +20nC respectively, they are separated by a distance of 0.23m.
a. What is the magnitude of the electric force between two spheres? Is this force attractive or repulsive?
b. What is the magnitude of the gravitational force between two spheres? Is this force attractive or repulsive?
2. Two protons are separated by a distance of 2.3×10^-10m in air.
a. Find the magnitude of electric force one proton exerts on the other. Is this force attractive or repulsive?
b. Find the magnitude of the gravitational force one proton exerts on the other. Is this force attractive or repulsive?
What are the effects of fuel price fluctuations on the household transport expenditure.
Critically debate (in an essay) how theories of sustainable economic development differ from classic theories of economic development. In the last three paragraphs, explain how theories of sustainable economic development have influenced the economic development of South Africa.
1.Solve the differential equation (2𝐷2 + 5𝐷 + 2)𝑦 = 𝑒-1/ 2 x
2. Solve the differential equation (𝐷3 − 3𝐷2 + 4𝐷 − 2)𝑦 = 𝑐𝑜𝑠𝗑.
Trace the following curves (x^2+y^2)x=2x^2+y^2
Use a Venn diagram to illustrate the subset of even integers in the set of all positive integers not exceeding 15.
What features of the respiratory system help protect it from the external environment? (Short answer please)
. In your opinion, state THREE long-term effects of workplace bullying and discuss THREE
ways in which one can deal with the effects you have mentioned
