Complete Question
A psychologist has designed an index to measure the social perceptiveness of elementary school children. The index is based on ratings of a child's responses to questions about a set of photographs showing different social situations. A random sample of 16 elementary school children was chosen, and their index measurements were recorded. Assume that the index measure in the population is normally distributed. The 95% confidence interval created from this data is (56.29, 65.09). This interval indicates:__________.Choose one or more:
a. The average index of elementary school children must be 60.69.
b. The standard deviation of the sample is about 10% smaller than the population standard deviation.
c. That if we take many samples from this population 95% of them will have a sample mean between 56.29 and 65.09.
d. 95% of all elementary school children in this district have indices between 56.29 and 65.09.
e. 4.40 is 95% of the true average of the index for all elementary school children.
f. We are 95% confident that the average index for all elementary school children is between 56.29 and 65.09.
Answer:
The correct option is a and f
Step-by-step explanation:
From the question we are told that
The sample size is n = 16
The 95% confidence interval is (56.29, 65.09)
Generally the sample mean(average index of elementary school children) is mathematically represented as

=> 
Answer:
Step-by-step explanation:
Given that a marketing research firm is estimating which of two sodas (A or B) college students prefer.
Sample size of 75 was taken at random.
Since sample size is sufficiently large i.e. >30, and also since samples are taken at random, we can assume that sample proportion
p=
follows a normal distribution with mean = 0.6 and variance = npq = 75(0.6)(0.4)
Yes, this sample is large enough to calculate a confidence interval.
Laura worked 32 hours and Gabriel worked 12
Let r represent the region bound by the graphs of y=sin(π x) and y=x³-4x.
Answer:
25
Step-by-step explanation:
4.5×5.5=24.75
so 24.75 is the area of the room but you have to buy whole tiles so you would need to but 25 tiles