Answer: The proportion of students spending at least 2 hours on social media equals 0.7257 .
Step-by-step explanation:
Given : The typical college freshman spends an average of μ=150 minutes per day, with a standard deviation of σ=50 minutes, on social media.
The distribution of time on social media is known to be Normal.
Let x be the number of minutes spent on social media.
Then, the probability that students spending at least 2 hours (2 hours = 120 minutes as 1 hour = 60 minutes) on social media would be:
Hence, the proportion of students spending at least 2 hours on social media equals 0.7257 .
Answer:
95.4% of family vehicles is between 1 and 3 years old.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 2
Standard Deviation, σ = 6 months = 0.5 year
We are given that the distribution of age of cars is a bell shaped distribution that is a normal distribution.
Formula:
P(family vehicles is between 1 and 3 years old)
95.4% of family vehicles is between 1 and 3 years old.
Answer:
It will cost $427.04 to paint deck and it will cost 958.485 to add fencing around deck
Step-by-step explanation:
Diameter of swimming pool = 27 feet
Radius of pool r=
Surrounding the pool is a deck that extends 5 feet from the edges of the pool
Outer radius R = 13.5+5=18.5
Area of deck = Outer area - Inner area
Area of deck =
Area of deck =
Area of deck =
Cost of painting 1 sq.feet = $0.85
Cost of painting 502.4 sq.feet =
Perimeter of deck =
Cost of fencing 1 foot = $8.25
Cost of fencing 116.18 foot =
Hence it will cost $427.04 to paint deck and it will cost 958.485 to add fencing around deck
Answer:
9.18% probability the miners find more than 16 ounces of gold in the next 1000 tons of dirt excavated
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean and standard deviation
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
What is the probability the miners find more than 16 ounces of gold in the next 1000 tons of dirt excavated?
This is 1 subtracted by the pvalue of Z when X = 16. So
has a pvalue of 0.9082
1 - 0.9082 = 0.0918
9.18% probability the miners find more than 16 ounces of gold in the next 1000 tons of dirt excavated