Description:
Sprint Nextel has the highest rate of customer churn (the number of customers who discontinue a service) in the cell phone industry, amounting to 2.45 percent. Over the past two years, Sprint has lost 7 million subscribers. Management wants to know why so many customers are leaving Sprint and what can be done to woo them back.

Requirement:
Does Data Mining help the company in unfolding the reasons behind why their customers are leaving? Explain why or why not.

Based on the information provided in the the beginning, answer the question

Critical Thinking Case HubSpot Focus on Flexible Benefits

What would your manager say to you if you came up with the idea of traveling with Justin Timberlake on tour for an entire year? This would not just be a work from home agreement but an actual out of office plan for one full-year sabbatical. That is exactly what happened at HubSpot when Rosalia Cefalu had a crazy idea that actually got approved. HubSpot, a global inbound marketing company, has approximately 19,000 customers in over 90 countries and 1,960 employees, stretching from Cambridge, MA, to Sydney, Australia. “We don’t think that culture is about free beer and ping-pong and dogs in the office, it’s about what you believe, why you do what you do, and who you choose to work with,” states CTO and cofounder Dharmesh Shah. Although HubSpot has plenty of free snacks on hand for their employees to enjoy, other flexible benefits HubSpotters enjoy are unlimited vacation time, tuition reimbursement, flexible hours, and an overall environment that balances freedom with accountability. At HubSpot it goes deeper than just the perks. The focus from the top down instills pride and passion within its employees, which then translates into happy customers. Although flexible benefits are a big perk of working at the third-best tech company to work for, according to Glassdoor’s annual Employee Choice awards, the culture isn’t for everyone. The company practices a sense of understanding, knowing that employees will move on and do not need to stay to be loyal and that sometimes someone is no longer needed—either because of performance, or changes in the company’s needs. This isn’t taken personally, and HubSpot is able to grow and continue to grow because it objectively sees the performance of its employees and what is best for the company and employee.

Questions: 1. How does HubSpot’s focus on culture affect employee performance? Chapter 8 Performance Appraisal and Rewards 283

2. What concerns would you have regarding giving employees countless flexible benefits such as HubSpot does; for example, a yearly sabbatical?

Here's an proposal on how to get from point A to point B in zero-gravity without using any propellant and the question why it wouldn't work:

A closed tube, filled with water and a round (solid) object. If you need equations, the volume of enclosed water is the same as the round object, but the round object is 10 times lighter. (imagine a glass with water plus a ping-pong ball).

On earth the round object will float on the water inside the tube (subject to one G).

In zero-gravity the round object has no preferred position.

If we accelerate the tube in zero-gravity by one G, the situation is the same as on earth, the round object "floats". In this example we are accelerating the tube from the left side to the right side. The round object will consider floating to the right AS LONG AS THERE IS acceleration.

Now consider adding a pipe to the bottom of the tube and connecting it to the top, a loop. Inside the pipe is a small water pump.

If we give this apparatus a push, say one G in a zero-g environment, the round object will move "up", but now we start the water pump and spray the water on the round object, we try to submerge it. It will resist and impart a impulse on the water. like trying to hose down a air balloon floating on the pool. The pump will feel a resistance and hence the whole apparatus will move.

Just running the pump at constant speed, same volume of water per second, will do nothing. but if we run the pump faster and faster the whole apparatus will start moving:

the amount needs to be geometrical. The point is that we need to keep the apparatus feeling an acceleration, since only then will the round-object "float" and resist the incoming water at the top, hence we have something to "push on".

Before you blow the "foul whistle": consider the situation if there were no round floating ball in the apparatus.

(the pump runs on solar power or pre-charged battery)

(disclaimer: i know standing on a sailboat and blowing into the sail will not get me anywhere, action<->reaction)

thanks a bunch Sklivvz for the edit. sometimes the idea just needs to get out, never the mind how it looks like : P

Coin taking game

This game is played between 2 players, player 1 and player 2. There are two piles of coins. The values of a coin can be any integer. Both players know the values of all coins in both piles. Player 1 makes the first move, and play alternates between the players. A move consists of taking a coin from the top of either of the piles (either player can take from either pile). The game ends when both piles are empty. A player’s score is the sum of the values of all the coins they took during the game. The player with the higher score wins.

1 Winning the coin taking game

In this task you will write a function best_score(pile1, pile2) in python to determine optimal play for the coin taking game. It will determine the highest score which can be achieved by player 1, assuming that both players play optimally.

1.1 Input

Two lists, pile1 and pile2. These lists contain integers which represent the values of the coins in the game. The numbers in pile1 are the values of coins in the first pile, where pile1[I] is the value of the coin with i coins beneath it in the pile. pile2 represents the coins in the second pile in the same way. The piles may be empty.

1.2 Output

A tuple with two elements. The first is a single number which represents the highest score which player 1 can achieve. The second represents the choices made by both players during the game (assuming optimal play). The choices are represented by a list containing only the numbers 1 and 2, where a 1 indicates that the player took the top coin from pile1 on their turn, and 2 indicates that the player took the top coin from pile2 on their turn.

If multiple sequences of choices are optimal, any of these sequences is acceptable.

Your insurance company has converged for three types of cars. The annual cost for each type of cars can be modeled using Gaussian (Normal) distribution, with the following parameters: (Discussions allowed!)

• Car type 1 Mean=$520 and Standard Deviation=$110
• Car type 2 Mean=$720 and Standard Deviation=$170
• Car type 3 Mean=$470 and Standard Deviation=$80

Use Random number generator and simulate 1000 long columns, for each of the three cases. Example: for the Car type 1, use Number of variables=1, Number of random numbers=1000, Distribution=Normal, Mean=520 and Standard deviation=110, and leave random Seed empty.

Next: use either sorting to construct the appropriate histogram or rule of thumb to answer the questions:

13. What is approximate probability that Car Type 3 has annual cost less than $550?

• a. Between 1% and 3%
• b. Between 27% and 39%
• c. Between 75% and 90%
• d. None of these

14. Which of the three types of cars is most likely to cost less than $400?

• a. Type 1
• b. Type 2
• c. Type 3

15. For which of the three types we have the highest probability that it will cost between $500 and $700?

• a. Type 1
• b. Type 2
• c. Type 3

A die is rolled. Find the probability of the given event.
(a) The number showing is a 2;
The probability is :

     
(b) The number showing is an even number;
The probability is :

    
(c) The number showing is greater than 5;
The probability is :     

Can you do 6 and 7. I'll give thumbs up

6. In a recent year, the SF Giants won 47 of 81 home games and they won 37 of 81 away games. Use a 0.05 significance level to test the claim that the proportion of wins for home games is greater than the proportion of wins for away games. Does there appear to be a home-field advantage?

7.In a recent year, the San Diego Padres won 45 of 81 home games and they won 31 of 81 away games. Use a 0.05significance level to test the claim that the proportion of wins for home games is greater than the proportion of wins for away games. Does there appear to be a home-field advantage?

In a recent year, Delaware had the highest per capita annual income with $51,803. Assume that σ = $4,850. A random sample of 39 state residents were selected.

What is the distribution of the sample mean income?

What is the probability that the sample mean income is greater than $50,800?

Why have gas turbine engines almost completely replaced piston engines on new corporate-sized twin-engine aircraft?