Martha surveyed 200 students at her school about the number of hours they spend
studying each day. The mean of the sample was 3.7 with a standard deviation of 0.46.
Martha can be 95% confident that the mean number of hours all the students at the
school are studying every day is 3.7 with what margin of error?
(Use the formula M = 1.96 x
where N is the sample size and s is the sample
standard deviation.)

What is the prime factorization of 23 ?me with this question

Martha has a deck of cards. she has lost some of the cards, and now the deck only contains nine spades, eleven diamonds, eight clubs, and twelve hearts. martha predicts that whenever she draws a card from the deck without looking, she will draw a club one-fifth of the time. which activity would best allow martha to test her prediction? a. randomly draw a card from the box and see if it is a club. b. randomly draw a card. then, continue to draw another card until all eight clubs are drawn. c. randomly draw and replace a card 120 times. then, observe how close to 30 times a club is drawn. d. randomly draw and replace a card 100 times. then, observe how close to 20 times a club is drawn.

Atorch and a battery cost 2.50 altogether.the torch costs 1.50 more than the battery.what fraction of the total price is the torch? give your answer in its simplest form.