Question

1. Consider the experiment of tossing three separate fair coins (and seeing which side comes up on each coin). Find the probability of getting exactly two heads.

a) 0.666                b) 0.375                c) 0.4                     d) 0.25

2. Find the area under the standard normal curve between z = -1.25 and z = 1.25.

a) 0.6412              b) 0.8817              c) 0.2112              d) 0.7888

3. The distribution of room and board expenses per year at a four-year college is normally distributed with a mean of $5846 and standard deviation of $1150. Random samples of size 20 are drawn from this population and the mean of each sample is determined. Find the probability of a sample with mean greater than $6000.

a. 0.275                      b) 0.447                       c) 0.553                 d) 0.786

Answer 1

SOLUTION-

1.) SAMPLE SPACE= { HHH, HHT, HTH, HTT, THH, THT, TTH, TTT}

P[ EXACTLY 2 HEADS]= 3/8 = 0.375

ANSWER- OPTION(B)

2.) AREA= P(-1.25< Z< 1.25)

=

=

=

=

ANSWER- OPTION(D)

3.) X ~ NORMAL( 5846, 1150)

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=

=

=

=

ANSWER- OPTION(A)

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