In a standard deck of cards there are 13 spades, 13 clubs, 13 hearts and 13 diamonds. the spades and the clubs are black. the hearts and the diamonds are red.
if two cards are chosen at random from a deck, one at a time, replaced after each pick, what is the probability that a black card is chosen first and a heart is chosen second?
options:
1/8
1/2
2/3
3/4

Now, martin can reasonably guess that the standard deviation for the entire population of people at the mall during the time of the survey is $1.50. what is the 95% confidence interval about the sample mean? interpret what this means in the context of the situation where 95 people were surveyed and the sample mean is $8. use the information in this resource to construct the confidence interval.