Unit So Dear - Flats Nama Dade Part 1 - Ch18 1. A group of amateur spelunkers were asked what is the most important gear to bring on a cave expedition. 0.84 said their flashlight, 0.58 said their helmet, and 0.45 said both flashlight and helmet. What is the probability that an amateur spelunker chosen at random a. Said flashlight or helmet? b. Said neither object? c. Said flashlight, but not helmet? d. Said helmet, but not flashlight? e. Given they said they liked the flashlight, then also said the helmet? f. Given they said they liked the helmet, then also said the flashlight? A group of high school band students were surveyed about what instrument they play and if they prefer solos or ensembles. 68% of the students said they play Trombone and enjoyed having solos. 94% said they did not play the Trombone and would like to be part of an ensemble. 53% of the students said they play the Trombone. a. Make a tree diagram showing the either they play or do not play the Trombone and if they would like to be a solo or part of an ensemble.b. What is the probability that a student chosen at random plays the Trombone and wants to be in an ensemble? c. What is the probability that a student chosen at random does not play the Trombone and wants to be a solo? d. What is the probability that a student chosen at random plays the Trombone and wants to be solo. Section 2 - Ch16 3. According to a survey of middle school students, 74% have a cell phone. If you asked 12 random middle schoolers, what would be the probability of: a. Exactly 4 students have a cell phone b. Fewer than 6 students have a cell phone c. Between 3 and 7 students have a cell phone. 4. Only about 45% of US adults know that they can help prevent forest fires. The state's Department of Natural Resources decides to survey 120 of your community members to find out if they know they can help prevent forest fires. Determine the following probabilities using a Normal Approximation to the binomial distribution. a. What is the Expected value (mean) of the data? b. What is the standard deviation of the data? c. Exactly 60 people know about forest fires. d Less than 42 people know about forest fires. s. Between 30 and 70 people know about forest fires