Q:must be taken in order to be 90% confident that the margin of error will not exceed 50 hours? Please show work

The 90% confidence z-value from the normal probability table is 1.645 Sample size n = [ (1.645) SD /error] ^2 n = {(1.645)(400)/50]^2 n =173.18 ≈ 174

Q:Do Jehovah's Witnesses sell solar or vacuum cleaners also as they go knocking door to door?

No, they sell lies and deception....and give literature for free.

Q:maybe Avon, books or vacuum cleanerswould my looks prevent me from making enough sales to earn a living

No!!! the tongue is fine but I would re think the hat xxx

Q:We know that black holes do not suck up everything in the universe; you have to cross the event horizon before you get sucked in forever. Does this make black holes comparable with vacuum cleaners? After all, vacuum cleaners do have a finite effective radius themselves

It's an interesting analog. Vacuums don't suck up energy, but black holes can.

Q:Where is the cheapest place to find a Dyson vacuum cleaner? I missed out on a sale at HomeDepot and am kicking myself for it! Anyone know someplace good?? They usually retail for $399. Thanks!

If you open up a Home Depot Consumer Credit Card, you can get 10% off and then there is no interest and no payments for 6 months. Otherwise try OKorder.

Q:Can you list all the companies that ever made vacuum cleaners and the names of the vacuum cleaners?

Me, either.

Q:I have had Sears vacuum cleaners, with beater bar and brushes, for over 40 years, now all of a sudden the bars have only brushes, no beater (to vibrate dust out of the carpet.) So I am wondering if ANY other company has them???.

I bought one at sears 9 months ago.

Q:Where in Bahrain can you find lamp shades, and Bissell vacuum cleaners?

Go down main abut 3 miles, make a quick left, go north on the one way street with the funny overpass, make a quick left then a right, it's right there on your left.

Q:Every vacuum I've had has broken. Two Bissells and Eureka. Cleanview Helix, The other Bissel is the powerforce compact, and the Eureka Optima. Anyways, the rollers stop rolling, and when I try to use them now, the smell of rubber is in the air. Is this from running over cat litter, and aquarium pebbles? Yeah, I tried replacing the belts, and cutting the hair off the roller, and they just don't work anymore. It's so frustrating. Been going through this for like two years now, and we went through two vacuum cleaners, this year!Should I see about changing the filters? Could that be it? So, so frustrating!!!!!!

You need to be more careful about what you are trying to vacuum. Vacuum cleaners are not meant to vacuum everything. Get a shop vacuum if you don't want to be careful. Shop vacuums can vacuum water!

Q:Is the one thing that separates us from animals is that we aren't afraid of vacuum cleaners?

No. I had some ants in my kitchen the other day, and they didn't appear afraid of the vacuum cleaner, although they should have been.