Answer:
The proportion of electric toothbrush prices are between 104.60 dollars and 108.20 dollars is 0.0099
Step-by-step explanation:
A set of electric toothbrush prices are normally distributed with a mean of 87 dollars and a standard deviation of 8 dollars.
Standard deviation = 
We are supposed to find proportion of electric toothbrush prices are between 104.60 dollars and 108.20 dollars i.e.P(104.60<x<108.20)
At x = 104.60
Z= 2.2
At x=108.20
Z= 2.65
Refer the z table for p value :
P(x<108.20)-P(x<104.60)=P(Z<2.65)-P(Z<2.2)=0.9960-0.9861=0.0099
Hence The proportion of electric toothbrush prices are between 104.60 dollars and 108.20 dollars is 0.0099
I believe the answer is B) 50
Answer:
0.6710
Step-by-step explanation:
The diameters of ball bearings are distributed normally. The mean diameter is 107 millimeters and the population standard deviation is 5 millimeters.
Find the probability that the diameter of a selected bearing is between 104 and 115 millimeters. Round your answer to four decimal places.
We solve using z score formula
z = (x-μ)/σ, where
x is the raw score
μ is the population mean = 107 mm
σ is the population standard deviation = 5 mm
For x = 104 mm
z = 104 - 107/5
z = -0.6
Probability value from Z-Table:
P(x = 104) = 0.27425
For x = 115 mm
z = 115 - 107/5
z = 1.6
Probability value from Z-Table:
P(x = 115) = 0.9452
The probability that the diameter of a selected bearing is between 104 and 115 millimeters is calculated as:
P(x = 115) - P(x = 104)
0.9452 - 0.27425
= 0.67095
Approximately = 0.6710
Answer:
x-7=13
Step-by-step explanation:
x-7= 13
hope that helps
