Question

1. a candy store owner wants to know the overall thoughts of customers in her store. she asks the first 20 customers who come into her store on a monday morning and ask them to rate there store experience on a scale of 1 to 10. her customers average response was a 8.8 and she concludes that all her customers have positive thoughts about her store. her conclusion is:

a) invalid, since the customers were chosen by b) unfair because she owns the store
convenience
c) spot on! d) valid, since customers were chosen randomly

1. select the equation that has an exponential growth of 7%

a) ( f(x)=7(1.1)^x ) b) ( f(x)=25(1.07)^x )
c) ( f(x)=25(0.93)^x ) d) ( f(x)=7(.99)^x )
10 a population characteristic is normally distributed. approximately what percentage of the population lies within three standard deviations of the mean?
a) 95% b) 34%
c) 99.7% d) 68%

Explanation:

Question 8

The store owner used a convenience sample (first 20 customers on a Monday morning). Convenience sampling is a non - random sampling method. A non - random sample may not be representative of the entire customer population. For example, Monday morning customers might have different shopping habits or preferences compared to customers at other times.

The general form of an exponential growth function is \(y = a(1 + r)^x\), where \(a\) is the initial value and \(r\) is the growth rate. If the growth rate \(r=7\%=0.07\), then the function is \(y=a(1 + 0.07)^x=a(1.07)^x\).

According to the empirical rule (68 - 95 - 99.7 rule) for a normal distribution:

• Approximately \(68\%\) of the data lies within \(1\) standard deviation of the mean (\(\mu\pm\sigma\)).
• Approximately \(95\%\) of the data lies within \(2\) standard deviations of the mean (\(\mu\pm2\sigma\)).
• Approximately \(99.7\%\) of the data lies within \(3\) standard deviations of the mean (\(\mu\pm3\sigma\)).

Answer:

A. invalid, since the customers were chosen by convenience

Question 9