According to an industry report, 26 percent of all households have at least one cell phone. Further, of those that do have a cell phone, the mean monthly bill is $55.90 with a standard deviation equal to $9.60. Recently, a random sample of 400 households was selected. Of these households, 88 indicated that they had cell phones. The mean bill for these 88 households was $57.00. What is the probability of getting 88 or fewer households with cell phones if the numbers provided by the industry report are correct?

0.034

Step-by-step explanation:

Given that:

Percentage of households with atleast one cell phone = 26% ; Hence, p = 0.26

Sample size (n) = 400

Using Normal approximation :

Mean(m) = n * p = 400 * 0.26 = 104

Standard deviation (σ) = √(n*p*(1-p))

σ = √(400*0.26*0.74)

σ = 8.7726848

X ≤ 88

Zscore = (x - m) / σ

Zscore = (88 - 104) / 8.7726848

Zscore = - 16 / 8.7726848

Zscore = - 1.8238430

Using the z probability calculator :

P(Z ≤ - 1.8238) = 0.03415

= 0.034

last option: rhombus or kite

step-by-step explanation:

a kite and rhombus have the same shape. as we don't have any specific formula for the calculation of area of kite. the diagonals are used to calculate the area of a kite or rhombus.

the formula for area of rhombus is given by:

here, d_1 is the first diagonal and d_2 is the second diagonal.

so,

last option is the correct answer ..

answer: this is not a question

step-by-step explanation: this is a answer