Pre-Calculus

posted by .

The table below shows a frequency distribution of the number of pickup trucks sold at 85 truck dealerships in Maine over an 18-month period.

Number of trucks sold/Number of dealerships:

70-90/2
90-110/11
110-130/39
130-150/17
150-170/9
170-190/7

Find the interval about the sample mean such that the probability is 0.90 that the true mean lies within the interval. (When P=90%, t=1.65)

I know that N=85, but I do not know how to find the standard deviation or mean in order to work the rest of the problem. Any help would be great.

  • Pre-Calculus -

    Frankly, I would assign numbers to do the mean, standard deviation.
    Change your frequency to actual data
    80,80, 100,100,100,100,100,100, (eleven 100's), 120 (39 of these). Your calculator can be your best friend doing this.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Pre-Calculus

    A car manufacturing company (the Company) can produce a car for $3000.00 and a truck for $5000.00. Suppose "C" cars and "T" trucks are sold to the dealer at mark-ups, respectively, of 20 and 30 percent. If the Company made a profit …
  2. Pre-Calculus

    The table below shows a frequency distribution of the number of pickup trucks sold at 85 truck dealerships in Maine over an 18-month period. Number of trucks sold/Number of dealerships: 70-90/2 90-110/11 110-130/39 130-150/17 150-170/9 …
  3. Algebra 2

    "At a school sponsored car wash, the fees charged were: $5 per car, $8 per truck, $10 per van. Twice as many cars were washed as pickup trucks. The amount collected for washing cars and pickup trucks was $360. A total of $410 was collected. …
  4. Math

    Below are the amounts of money a waiter earned each day last week. $120 , $170 , $150 , $190 , $130 , $200 , $160 . What is the interquartile ?
  5. Math

    Sales made last year by Lane's Appliance Store are listed below. The first number tells how many employees made the sales amount. Two sales employees earned in the range of $130,001-$150,000. Six sales employees earned in the range …
  6. econ

    Consider the market for trucks. Assume that the demand for trucks is given by 60 2 5 D Q P Y where P is price per truck and Y is the income of the buyers. The supply of trucks is given by 30 5 3 S Q P W where W is the price of all …
  7. math

    Thirteen bowlers were asked what their score was on their last game. The scores are shown below. 190, 150, 154, 194, 182, 190, 170, 151, 190, 170, 178, 161, 180 Find the range of the bowlers’ scores.
  8. math

    In one month a salesman sold a total of 30 cars and trucks. If three times the number of cars sold equals twice the number of trucks sold, how many trucks did he sell?
  9. Life Management

    The Lemon Law pertains to: a. new cars and trucks*** b. used cars and trucks c. only vehicles purchased from the dealerships
  10. math help

    The number of trucks registered in a city increases by 10% each year. Initially, there were 100 trucks registered. There were 110 trucks registered at the end of Year 1. What is the number of trucks registered in the city at the end …

More Similar Questions