Question

Need some assistance:

1. In a standard normal distribution, what is the percentile score of a data point with a Z-score of 1?

50.00

84.13

93.33

97.73

2. Mean hourly wage in the construction industry is $19.45 and standard deviation is $3.94. What is the probability that a worker receives less than minimum wage, which is $14/hour?

4.75%

8.33%

91.67%

95.25%

3. The average price of milk available in supermarkets in 2015 is $4.98/gallon. The standard deviation is $0.72. What is the probability that you could buy milk within a range of $4.50 to $5.50 if you went to a similar supermarket?

26.63%

51.24%

75.90%

94.32%

THANK YOU!!!

Answer 1

solution

(A)P(Z<1)=0.8413

answer = 84.13

(B)Solution :

Given that ,

mean = = $19.45

standard deviation = =$3.94

P(x <$14 ) = P(( x -) / (14 - 19.45) /3.94 )

= P(z < -1.38)

Using z table

=0.0833

=8.33%   

(c)

Solution :

Given that ,

mean = = $4.98

standard deviation = = $0.72

P($4.50< x <$5.50 ) = P[(4.50 - 4.98) / 0.72< (x - ) / < (5.50 - 4.98) /0.72 )]

= P( -0.6667< Z <0.7222 )

= P(Z < 0.7222) - P(Z <-0.6667)

Using z table,  

= 0.7649 -0.2525

= 0.5124

=51.24%