Kaplan Business School STAM4000
Practice Quiz
Question 1.
You are told that the weights of bags of apples are normally distributed with a mean of 1
kilogram and a standard deviation of 0.105 kilogram. According to the Empirical rule,
within what range will approximately 99.7% of the bags of apples weigh? Please give
your first answer as the lower bound and your second answer as the upper bound.
Give your answers correctly rounded to two decimal places.
Answer: Mean= 1 kg ; standard deviation = 0.105kg
μ ± 3σ
= 1 ± 3x0.105
= (0.685,1.315)kg
Approximately, 99.7% of the bags of apple weigh within the range of (0.685,1.315)kg
Lower Bound:0.685 Upper Bound: 1.315
Question 2.
A marketing analyst for a chocolatier claims that 85% of individuals purchase milk
chocolate. If a random sample of 50 consumers is selected, what is the Z score if 40%
of those sampled purchased milk chocolate? Assume the conditions are satisfied.
Answer: Z= (phat -p)/(sqrt(p(1-p)/n))
= (0.4-0.85)/(sqrt(0.85(1-0.85)/50)
Z score =-8.91
Question 3.
Practice Quiz
Question 1.
You are told that the weights of bags of apples are normally distributed with a mean of 1
kilogram and a standard deviation of 0.105 kilogram. According to the Empirical rule,
within what range will approximately 99.7% of the bags of apples weigh? Please give
your first answer as the lower bound and your second answer as the upper bound.
Give your answers correctly rounded to two decimal places.
Answer: Mean= 1 kg ; standard deviation = 0.105kg
μ ± 3σ
= 1 ± 3x0.105
= (0.685,1.315)kg
Approximately, 99.7% of the bags of apple weigh within the range of (0.685,1.315)kg
Lower Bound:0.685 Upper Bound: 1.315
Question 2.
A marketing analyst for a chocolatier claims that 85% of individuals purchase milk
chocolate. If a random sample of 50 consumers is selected, what is the Z score if 40%
of those sampled purchased milk chocolate? Assume the conditions are satisfied.
Answer: Z= (phat -p)/(sqrt(p(1-p)/n))
= (0.4-0.85)/(sqrt(0.85(1-0.85)/50)
Z score =-8.91
Question 3.
