Use the information in
[link] to answer the following questions.
Find the 30
^{th} percentile, and interpret it in a complete sentence.
What is the probability that the age of a randomly selected smartphone user in the range 13 to 55+ is less than 27 years old.
Let
X = a smart phone user whose age is 13 to 55+.
X ~
N (36.9, 13.9)
To find the 30
^{th} percentile, find
k such that
P (
x <
k ) = 0.30.
invNorm(0.30, 36.9, 13.9) = 29.6 years
Thirty percent of smartphone users 13 to 55+ are at most 29.6 years and 70% are at least 29.6 years.
Find
P (
x <27)
normalcdf(0,27,36.9,13.9) = 0.2342
(Note that normalcdf(–10
^{99} ,27,36.9,13.9) = 0.2382. The two answers differ only by 0.0040.)
There are approximately one billion smartphone users in the world today. In the United States the ages 13 to 55+ of smartphone users approximately follow a normal distribution with approximate mean and standard deviation of 36.9 years and 13.9 years respectively. Using this information, answer the following questions (round answers to one decimal place).
Two thousand students took an exam. The scores on the exam have an approximate normal distribution with a mean
μ = 81 points and standard deviation
σ = 15 points.
Calculate the first- and third-quartile scores for this exam.
The middle 50% of the exam scores are between what two values?
A citrus farmer who grows mandarin oranges finds that the diameters of mandarin oranges harvested on his farm follow a normal distribution with a mean diameter of 5.85 cm and a standard deviation of 0.24 cm.
a. Find the probability that a randomly selected mandarin orange from this farm has a diameter larger than 6.0 cm. Sketch the graph.
if sample size n very large and probability tends to 0.5
if these both conditions are satisfied by binomial distribution it would tends to normal distribution
sravani
n tends to infinite i.e large
Probability tends to 0 i.e indefinitely small.
np = lamda
Anji
the above is poison to Bin
Anji
no of trails n tends to indefinitely large..i.e infine
neither p nor q is very small
Then bin tends to normal
Anji
if the death of of the snow is my yard is normally distributed with the m is equals to 2.5 and
what is the probability that a randomly chosen location with have a no that between 2.25 and 2.76
A consumer advocate agency wants to estimate the mean repair cost of a washing machine. the agency randomly selects 40 repair cost and find the mean to be $100.00.The standards deviation is $17.50. Construct a 90% confidence interval for the mean.
Sixty-four third year high school students were given a standardized reading comprehension test. The mean and standard deviation obtained were 52.27 and 8.24, respectively. Is the mean significantly different from the population mean of 50? Use the 5% level of significance.
Simple Bar Chart is a Diagram which shows the data values in form of horizontal bars. It shows categories along y-axis and values along x-axis. The x-axis displays above the bars and y-axis displays on left of the bars with the bars extending to the right side according to their values.
add all the data and divide by the number of data sets. For example, if test scores were 70, 60, 70, 80 the total is 280 and the total data sets referred to as N is 4. Therfore the mean or arthritmatic average is 70. I hope this helps.
Jim
*Tan A - Tan B = sin(A-B)/CosA CosB ...
*2sinQ/Cos 3Q = tan 3Q - tan Q